# Whats the best way to oxygenate your water?



## Cento

Now I remember some rubbish about brownian motion or whatever in highschool, but as far as practicality is concerned, I still don't understand whats the best way to get O2 into water...

I myself find bubbles unacttractive and un-natural, but I know that my HOB's broke the surface of the water and that was sufficient enough to oxygenate the water (one had a bio-wheel).

But recently I switched to a canister filter for many reasons (noise reduction, cleanness of setup, efficiency, bragging rights, etc etc), but now it leads me to wonder about oxygenation. I have a powerhead with a filter media cage running in there creating quite a current, and the spraybar is an inch below the surface creating a decent little current. However, the surface is never really "broken".

My question boils down to: is it necessary to "break the surface" to get oxygen into the water or is movement sufficient?


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## RyanR

Bubbles are mostly useless, except for helping the water move as they rise up.

Really, surface movement (and good circulation of the water in general) is sufficient in a perfect world, just keep an eye out for "scum" on the surface that basically kills the interface of water and air.

I've found that a powerhead really helps keep the water circulating.

-Ryan


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## BioG

Not necessary but ideal. If you can visually see flow at the surface you're fine (Even though you're probably fine anyway with good turnover. I occasionally use a power head aimed diagonally upward to barely break surface . If you filter with a sump using an over flow system none of this is necessary.

In my sumped tanks I still use a powrhead in the same manner but I use a small one that's far away from the overflow because I want the surface skimmer to collect all that garbage on the surface.

If their is a film over your tank it's not getting turned over properly so you can judge by that too. ALl this also depends on what your keeping i.e. labyrinth fish are fine in low oxygen tanks.


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## Cento

Thanks for the tip Ryan!

BioG, I'll be keeping Mbuna, so I know they're used to well oxygenated water. Yeah, I knew that The wet/dry filters would be the most ideal for aeration. Sadly I didn't have to space (or patience) to create a sump in my cabinet, or the $$$ to afford the awesome EHEIM Pro Wet/Dry canister filter..

I'm glad to hear you think surface breakage isn't necessary, 'cause that was the biggest pro of a canister filter for me. While eating dinner, or watching a movie at the most dramatic part, you don't have to hear that water running in the back.


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## Morcs

You could always rig up your output on a bracket or something so its above the tank causing a wee drop?

I have a duckbill on my canister, and it moves a lot of water - the current can be seen near the surface if food ever gets caught in it - yet yes I still have that oily-scum stuff on the surface - and thats with x8 filtration.


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## dipseydodunkaroo

can you over oxygenate the water? I have korilia's with an air stone under them and it puts out a lot of oxygen is this ok for the fish?


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## BioG

It depends on what fish you're working with. You could have too much oxygen though that in and of itself wouldn't be the problem. Meaning excess oxygen could initiate unhealthy levels of bacterias, algaes etc. Don't worry though I've never actually heard an account of anyone doing it. usually too much flow etc. will stress fish to deathh way before too much oxygen will.

By creating "micro-bubbles" with an airstone and a fan (Koralia) you're not actually injecting the tank with anything except micro-bubbles. Micro bubbles or any size bubbles only move water as they pass through it helping to bring new water to the surface, they then break the surface film and burst which aids in the exchange of gases at the surface only. This all makes airstones sound very beneficial but they're really not. It would take a whole lot of noisy (pumps), messy (Calcium and junk from bubbles bursting), ugly (I don't like the look of bubbles) bubblers to equal the amount of turnover/surface agitation a #2 Koralia can do clean and silent.

When incorporated with large sponge filters bubbles do wonders but they're still ugly


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## Cento

Morcs, I just might try that "spray bar above the water" thing later on down the road if the water looks oxygen depleted......hmmm

:?

Which leads me to another question, is there a way to test for dissolved oxygen in the water?


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## BioG

There are tests for that but your fish will tell you if you're low. I should say cihlids will tell you, or any bottom dwelling fish. If you'r seeing mbuna, for example, skimming the surface with their lips above water, open your tops and turn on power heads/bubblers.

If you're keeping cichlids, except for goby cichlids, you'd do just as well putting those spray bars in the water aimed up at an angle causing surface agitation quitely without too much flow. LAke Malawi and Lake Tanganyika have very little current so they in turn require little current in the aquarium. A good rule of thumb is that non-riverine fish should not have to swim to stay in one spot in your tank (Again, gobies being the exception as they are surge fish and will swim right in front of your powerheads or sump returns just to get tossed around).


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## BioG

Too much oxygen and too little tends to cause different but unique stinkiness to your water as well. If your water smells "clean" then it's probably reltively so.


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## Toby_H

As long as the surface has waves... it is likely you have enough agitation...

As mentioned, the fish will let you know if there isn't enough oxygen...

I do not believe that we could possibly saturate our system with enough oxygen to be harmful to our fish nor our systems biological balance...


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## boredatwork

Even better than a spray bar is a surface skimmer. I can't imagine owning a canister without one of these. It will also keep your surface water cleaner than a spray bar. And it effectively guarantees that your water is constantly being aerated. As long as you have decent flow in your tank I don't think anything more is necessary.

http://www.marinedepot.com/Tom_Aquatics ... sories-Tom`s_Aquatics-OE1138-FIFRFASE-vi.html

To measure oxygen in your water you can buy a dissolved oxygen meter, they usually cost about $150-$200.

Convention states that unless your fish are sucking at the surface of the water, then there is enough oxygen. This isn't a conclusive argument, but it seems to work well enough.


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## steelers fan

> Bubbles are mostly useless, except for helping the water move as they rise up.


surface agitation is the way to get O2 into the water...some people dont like the looks of the bubbles but in terms of surface agitation nothing does that more than a bubble curtain...if you have ever seen one working you would agree.


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## Cento

Boredatwork.. I am intrigued by the surface skimmer idea. I have an EHEIM 2213, so I checked out EHEIM's surface skimmer review here; it didn't seem too promising. Mind you there was only a couple reviews if i remember correctly.

I'm gonna look more into it thou.. seems easy enough of a modification to increase surface agitation. As for the dissolved oxygen test for over $100, I'll pass.... :wink:


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## boredatwork

Several studies have shown that bubbles are pretty much useless when it comes to oxygenation. And not to mention they are ugly and noisy.

I have seen that Eheim has their own version of a surface skimmer. It is different than the one I posted, and much more expensive.

If you search the forums for "surface skimmer canister" I think you will find lots of people that are happy with the cheap $10 version. You may need to buy some extra parts to make it work with the Eheim.


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## Toby_H

boredatwork said:


> Several studies have shown that bubbles are pretty much useless when it comes to oxygenation. And not to mention they are ugly and noisy.


I have seen/read articles explaining how the bubbles themselves do very very little for oxygenation... but the agitation they create at the surface does what agitation does... which is oxygenate the water.

The purpose of this study/article was to show people you do not need bubbles... you need surface agitation... and there are many ways to get surface agitation... bubbles are but one of many...

I'm not necessarily pormoting the use of bubbles... just trying to keep them on the list of options...


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## Cento

I haven't seen these studies myself, though I'd like to take a look at them, even to see what they have to say about oxygenation in itself. Sounds intersting.

*Boredatwork*, by the time you sent your post, I had already gone out and bought the EHEIM version of the surface skimmer... 

I'm fine with that though, becuase I held in my hand the aquaclear version and the EHEIM version, and I personally felt like the EHEIM version feels stronger, or more well built. Anyway, to each his own.

I've had it installed for 10 minutes as of now, and I"m happy with it so far... :wink:

In a month or 2, I'll post a review. Thanks to all who posted! Very educational!! I learn so much at this forum; its very helpful to a hobbyist. Some people speak ill of forums in gereral, and say that you don't know the credibility of the sources. However, here, over the past 4 years, I've ALWAYS found feed back very helpful and informative. Thanks again guys!


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## steelers fan

yeah the bubbles themselves do nothing its when they break at the waters surface is when the exchange takes place...and *** never seen more surface agitation than with the bubbles...unless you have a strong currant


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## boredatwork

I know I have read at least two articles that make the argument that bubbles are effectively useless. I can try to find them.

I understand that oxygenation comes from surface agitation. However, that is a very limiting statement. Even still water will have oxygen exchange at the waters surface. To be more effective than still water good water flow to circulate freshly oxygenated water from the surface throughout the tank.

Unless you have a massive bubble system when a bubble floats to the water surface is can only effect a small amount of water movement on the surface of the water. Very little water is being recirculated throughout the tank as a direct results of the bubbles. So you can think of it as oxygenation on a small portion at the top of the water column, which an be done without the bubbles.

If you have any kind of filter in the tank it will be way more effective since it can circulate water throughout the height of the water column. Using your filter to provide good water flow is a much more effective solution, and since most tanks have a filter the contribution of the bubbles is probably negligible.


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## Toby_H

â€œSurface Agitationâ€


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## Cento

So, just an update on the surface skimmer I purchased based on advice from a fishkeeper in this thread..

Its working quite well! :thumb: Wanted to also mention, that the particular one I bought (EHEIM) has a little spiral funnel device to spin the water down the tube after its skimmed off the surface (why? I don't know).

Well, on its way down, it makes...... yes, hundreds of bubbles. So I know that may or may not add to the discussion that many thought was over. I wonder, if all the theories presented here on bubbles, still apply when the bubbles are funneling down a tube engulfed in water and on its way to the filter.. I would think yes... Anyone?


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## GotTanked

Just as an FYI, your water isn't an O2 vacuum, it exists fairly close to equilibrium. This is why plants can pearl underwater, the water is saturated and can't diffuse the O2 so it just rises.

Now this could potentially (extreme worst case scenario) be caught in pockets with waste under sand and fuel bacteria colonies... but I can't really imagine what sort of tank set-up you'd need for that.


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## nick a

I've got a slightly differing POV on this topic.

Agree, with Toby that the water and the atmosphere are constantly trying to work towards a definable point, that protein scum/film on surface impedes the process and also agree that circulation throughout the tank is a must.

Disagree that somehow surface tension is involved with the molecular activity going on with the hydrogen & oxygen. IMHO, the purpose of agitating the surface is to increase the surface area that the activity has to take place. Picture still, FLAT water--distance from point A to point B. Picture same distance, but now with waves rippling. You math wiz's can calulate the increased surface area created by even 1/4" ripples over any given tank size.

That said, the entire surface area of any bubble is by definition increasing the total surface area for liquid/gas interchange. Anyone care to calulate out the surface area of all those spheres traveling thru the water column?

Bubbles alone are fine. UGFs & box filters driven by air pumps were just about all we had when I started out in this hobby and everything worked well. Nowadays, with all the other options available, bubbles are no longer necessary but


> I know I have read at least two articles that make the argument that bubbles are effectively useless.


they were and are far, far from useless.


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## Toby_H

A sphere with a Â¼â€


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## nick a

:lol:

I'm not going to quibble with your math, although I find the measurement of .01" bubbles interesting  --your vision is much better than mine! To whatever degree, bubbles provide a net gain in gas/liquid contact in addition to (A) generating turbulence at the surface & (B) moving water from the lower zone of the tank to the upper.

I think we are in general agreement /just saying things slightly different.

I'm still not sure what the 'surface tension' issue is tho. You agree that as water temperature increases dissolved oxygen rates decrease. However as described here:
http://hyperphysics.phy-astr.gsu.edu/Hbase/surten.html#c3
The surface tension actually decreases with increases in temperature. So it would appear that if there is any correlation between surface tension and DO--it would be opposite of what you seem to be saying.

This is from the NCSU Water Quality Group and is a pretty good read
General Information: Dissolved oxygen (DO) refers to the volume of oxygen that is contained in water. Oxygen enters the water by photosynthesis of aquatic biota and by the transfer of oxygen across the air-water interface. The amount of oxygen that can be held by the water depends on the water temperature, salinity, and pressure. Gas solubility increases with decreasing temperature (colder water holds more oxygen). Gas solubility increases with decreasing salinity (freshwater holds more oxygen than does saltwater). Both the partial pressure and the degree of saturation of oxygen will change with altitude. Finally, gas solubility decreases as pressure decreases. Thus, the amount of oxygen absorbed in water decreases as altitude increases because of the decrease in relative pressure (Smith, 1990). 
Once absorbed, oxygen is either incorporated throughout the water body via internal currents or is lost from the system. Flowing water is more likely to have high dissolved oxygen levels than is stagnant water because of the water movement at the air-water interface. In flowing water, oxygen-rich water at the surface is constantly being replaced by water containing less oxygen as a result of turbulence, creating a greater potential for exchange of oxygen across the air-water interface. Because stagnant water undergoes less internal mixing, the upper layer of oxygen-rich water tends to stay at the surface, resulting in lower dissolved oxygen levels throughout the water column. Oxygen losses readily occur when water temperatures rise, when plants and animals respire, and when microbes aerobically decompose organic matter.

http://www.water.ncsu.edu/watershedss/info/do.html

And here is a snippet I found helpful from an old textbook:

"Dissolved oxygen concentrations increase wherever the water flow becomes turbulent, such as in a riffle area, waterfall, or a dam. Oxygen concentrations are much higher in air, which is about 21 percent oxygen, than in water, which is a tiny fraction of 1 percent oxygen. *{the following is your 'want'}* Where the air and water meet, this tremendous difference in concentration causes oxygen molecules in the air to dissolve into the water until saturation is reached. *More oxygen dissolves into water when turbulence caused by rocky bottoms or steep gradients brings more water into contact with the surface. More oxygen dissolves into water when wind stirs the water; as the waves create more surface area, more diffusion can occur.* A similar process happens when you add sugar to a cup of coffee. The sugar dissolves, but it will dissolve more quickly if you stir the coffee."


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## zazz

that last post needs some serious digestion...

but another angle on this discusion is that spray bars slow down the circulation of the canisters...of course this is true ..they represent an artificial barrier to their opperation. so once removed I supplemented the spray bars with two surface level powerheads with the bubble option installed.

so they fire across just under the surface and cause huge ammounts of surface aggitation ..thus replacing the spraybars.

for me this is just perfect and the fish are happy :dancing:


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## Toby_H

I completely agree I am estimating bubble sizes as well as quantities in the tank at a given moment. If I were to use 225 .25â€


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## Cento

Alrighty then... what about Supersaturation. Is it possible, (especially in planted tanks or those of you who have well water), to have TOO much oxygen.. There were reports in the wild that 20,000 salmon died due to supersaturation of oxygen in the water causing a gas embolism in the fish.

This link was very very interesting... 

http://www.env.gov.bc.ca/wat/wq/BCguide ... #TopOfPage


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## mncherie1

jayhayward10- why are you shamelessly plucking this book in every post? The sole purpose of forums like this is to learn from many people's experiences. Try advertising on Amazon


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## nick a

Yes, and for only $20



> I have no doubt that if you grab your copy of The Complete Guide to Freshwater *Aquariums*, and put it to use, you will end up with a happier, healthier *parrot* that will be your friend for years to come... Plus you will have some incredibly fun times with your *bird*


 :thumb: =D> :?
Not to mention all the other "closely guarded secrets" like 


> Instructions on just how often to change the water in your freshwater aquarium and why.


Enquiring minds like mine want to know.........


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## Cento

Wow.. I don't know what happened here.. but back to the discussion, after reading the link I listed earlier, I'm not too sure that the attitude of "there's no such thing as too much oxygen" is as sound as I thought.


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## nick a

While it is possible to over saturate with DO, I've never heard anecdotes or read anywhere that this is anything worth wasting any concern over as far as the hobby goes.


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## Toby_H

nick a said:


> While it is possible to over saturate with DO, I've never heard anecdotes or read anywhere that this is anything worth wasting any concern over as far as the hobby goes.


I completely agree that while oversaturation is possible in rivers and other natural conditions... it is nothing we will ever have to worry about in our aquariums...

Oversaturation in natural environments may be a concern in or after rapids in a shallow cold water river... but not in our 80*F aquariums with little ripples and air bubblers


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## Cento

I believe this site will change you're mind......................... 

http://iweb.tntech.edu/dcrouse/trekques.htm


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## Toby_H

But isnâ€™t the oxygen mole fraction for all of earth .21?â€¦

Isnâ€™t the â€œpressureâ€


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## boredatwork

Oversaturation of dissolved oxygen is a bit of a misnomer. There really is no such thing. The reason come from the fact that there is no standard level of "saturation", so you can't have a relative over saturation.

For example, I know from other hobbies that also consider dissolved oxygen a critical metric, that if you took a bucket of still standing water and measured the DO it would be about 4ppm (approximately at room temperature). If you take an aeration stone and push air through it you could bump it up to about 10ppm. If you take an aeration stone and pump pure oxygen through it you can increase the DO to over 20ppm. But, if you shut off the aeration/oxygenation than the amount of DO will decay, eventually back to the 4ppm. So, do you consider the 4ppm saturation since that is the equilibrium? Or is the regular air saturation since that is the most you can do under "normal" circumstance? Or is the 20ppm saturation since that is when it maxes out (which is what saturation normally refers to).

If the 4ppm is saturation, then everything else is over saturation (literally). If the 20ppm is saturation, then I am not sure how you do better than infused O2, so then there cannot be any oversaturation.

At the end of the day, I am not sure why this matters, haha.

To go back a few posts to my earlier point. Bubble devices are useless. What I should say is that bubble devices are useless when compared to almost any type of power filtration.

There needs to be a distinction between aeration and circulation. To maximize oxygenation you need both. Bubble devices can be minimally effective at aeration at the surface of the watter, but they do not do a good job at circulation (unless you have a really extreme setup). It has already been stated that bubbles do not aerate until they hit the surface of the water - at which point they do very little to circulate the oxygenated water throughout the tank. In other words you end up oxygenating already oxygenated water. But that oxygenated water is not spread throughout the tank.

Now, if you have good water flow from a filter that could provide circulation that would make the bubble device more effective. The problem is that by using a filter, you are making the bubble device obsolete because the filter can perform both circulation and therefore aeration much more effectively. This is why bubble devices are useless. Without a filter they do not provide circulation. With a filter, the filter does a better job at aeration anyway.

So, in my opinion, there is no need for a bubble device. Just use your filter to provide movement at the surface of the water and you will provide a source of oxygen exchange for your water.


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## Toby_H

While I agree with just about everything your saying BoredAtWorkâ€¦ I still feel you are exaggerating your conclusion of â€œbubblers are uselessâ€¦

Yes they generally create far less water movement than other forms of filtrationâ€¦
Yes other forms of filtration can be used for more effective surface agitationâ€¦

I still feel there are situations where bubblers can be used as an asset, thus making them more than â€œuselessâ€


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## Toby_H

Toby_H said:


> While I agree with just about everything your saying BoredAtWorkâ€¦ I still feel you are exaggerating your conclusion of â€œbubblers are useless"â€¦
> 
> Yes they generally create far less water movement than other forms of filtrationâ€¦
> Yes other forms of filtration can be used for more effective surface agitationâ€¦
> 
> I still feel there are situations where bubblers can be used as an asset, thus making them more than â€œuselessâ€


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## nick a

I think the term 'useless' is useless in this conversation. The entire early history of this hobby has shown that fish can quite successfully be raised in aquariums with nothing but air driven stones, box filters and UGFs. You can walk thru very large and very well stocked fish stores today that use nothing but a air blower........yada yada.

Are there more modern, very arguably 'better' options available today for the hobbyist--you bet!

50% of the tanks in my fishroom are run by nothing but air stones & sponges and all the fish in them seem to be quite satisfied with the 02 level their habitat.

If it works in the circumstances it is applied to, it can hardly be so casually called useless.........


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## boredatwork

I won't disagree there is a use for them, but like you said, those tend to be rare cases as opposed to the norm. If I had a fry tank, I would probably go with a sponge filter not an FX5.

And that is why I qualified my statement. Bubblers may not be objectively useless, but if you have a power filter in your tank, that is going to provide far superior oxygenation, and therefore in my opinion relegates the purpose of the bubbler to noting more than aesthetic.

And in regards to your example of canister usage (and tying it back to the OP), that is one reason I love the canister surface skimmer. That, and it gives sump lovers/canister haters one less thing to boast about.


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## nick a

As I said, you seem to forget your hobby's history with your 'rare'--at one time, it was the ONLY :thumb:

But beyond semantics and history........

This topic got me thinking. I would rephrase the OP's original ? with this one:

What is required for *adequate *oxygenation? (Adequate being defined as the amount necessary to maintain a population of happy, healthy & thriving fish)

Some general rules that come to my mind that could be applied:
1. Do not overfeed
2. Vacuum substrate for any 'post-digestion food' :wink:/organic debris during regular WCs
-----1 & 2 because the organic decay process "uses" oxygen
3. Use the appropriate level of filtration/circulation for your fish stocking level/tank set up.
4. Maintain items used for 3 regularly to keep at optimum operation & avoid them contributing to organic build-up.
5. Nature will take care of the rest.

Can't really add anything about plants -'cause i have no real experience with that aspect.

Sorta beginning to sound like basic fish keeping practices.....

Feel free to critique/ modify/add to this list :thumb: (Psssst--but don't give away any closely guarded secrets of the hobby :lol


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## nick a

BTW--worthwhile read IMHO http://www.reefkeeping.com/issues/2004-09/rv/feature/index.php


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## boredatwork

I am not exactly sure of the relevance. To me that says that bubble makers are a thing of the past, and that now there are much better things to use. I won't deny their existence or usefulness at some point in time, but it doesn't make them a good or necessary option today.


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## boredatwork

To be honest, if you rephrase with that question, I would say you don't even need to pay any attention to good circulation or surface movement. I am sure that 80% of the fish tanks out there do not think about oxygenation let alone "the best setup". They go to the store, buy a tank, a cheap filter, and put some fish in it, and they are fine.

It is my guess that if you are thinking about maximizing oxygenation then you are in a small percentage, and you are thinking above and beyond adequate.


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## BioG

Okay I think we've talked enough about air! :lol:

There are a lot of lonely posts about fish on this site :fish:

kidding


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## lloyd

boredatwork said:


> It is my guess that if you are thinking about maximizing oxygenation then you are in a small percentage, and you are thinking above and beyond adequate.


 me and 10 million dead goldfish say your wrong.


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## KaiserSousay

While quite interesting to bandy our thoughts about, I for one, always pick up a few "golden nuggets" of info. We seem to have drifted away from the original question. 
Whether we have drifted on an air bubble or been pushed by a current of water, move we have, none the less. :roll: 
At this point, can we agree on "the best way to oxygenate your water" or not? :-?


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## lloyd

KaiserSousay said:


> At this point, can we agree on "the best way to oxygenate your water" or not? :-?


 -water circulation combined with nitrate control.
the key role of water circulation, is to assure the majority of waste is collected into our filtration devices. turbidity is much more important than agitation. then, we need to test nitrates, to assure our maintenance schedule keeps this equipment running at an optimum level. these two responsibilities combine to limit organic populations, allowing the less efficient life forms less competition for oxygen. this is especially important, and best witnessed, during power outages. a well maintained aquarium can last for days without intervention, while 'dirty' systems go bust overnight without frantic water changes.


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## Toby_H

I think we can confuse ourselves and start goofing up if we narrow our focus too much. Stepping back and viewing 'the big picture' gives us a better perspective...

Water Circulation is important in for quite a few things and is an essential part of a healthy aquarium. If we only consider water circulation in regards to oxygenating our water we can miss out on some of it's other benefits...

The same can be said about many many aspects of an aquarium...

But at the same time I think that conversations such as this, where we 'over analyze' a certain aspect gives us a more thorough insight to the functions that are taking place in our aquariums which allow us to better anticipate potential problems and avoid them.

In my experience... if we cover the basics to keep "a healthy aquarium"... oxygenation just happens... I've just never seen a well filter, properly stocked, clean aquarium suffer from a lack of oxygen in the water...


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## KaiserSousay

> I think we can confuse ourselves and start goofing up if we narrow our focus too much


Kind of "can`t see the forest, for the trees". 
I agree. 
Like I said, I always glean a bit of new info out of these kind of threads. 
Must admit to a chuckle on occasion, as a participant starts to loose their cool..must be the "devil" in me.  
After a review of all, if I were to say, surface water movement/agitation was the best way, would we reach agreement? 
Then it would just be a matter of amount of movement, with the various methods we use to achieve it.


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## Cento

Yes. Makes the most sense to me.. I went ahead and put some of the advice to practical use in my aquarium long before everyone began getting into the "thick" of the discussion... 

It certainly wasn't my intent to start a "heated" debate, so sorry for any damage done by that. However, like I said, I got some pretty good advice on how to achieve what I was looking for; went ahead and put it into practice, and now things are peachy keen in my aquaria! 

Thanks to all who contributed.. Most knowledge of this hobby I have has come from this Forum.. not really from books.. I mostly am disapointed with books, other then species-specific information.. So, thanks again guys! :thumb:


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## lloyd

KaiserSousay said:


> ...After a review of all, if I were to say, surface water movement/agitation was the best way, would we reach agreement?...


 IMHO, #1 would be 'limiting biological load'. every other mentioned tool would cause an immediate digression if ever removed from the ecosystem.


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## boredatwork

Why the damper?

Honestly, after about a year of participating on this site, these are the only kinds of threads that interest me anymore. For most of the topics I can only barely stop myself from belligerently pointing people to the Search icon. (Although, to be fair, this discussion has ensued many, many times...may I kindly point out the Search icon?)

Plus I don't think any of us are getting any dumber from this discussion.

Now, getting that out of the way, there were several claims made that I still think have not been clearly addressed.

*lloyd* I would disagree about your point #1. I think if you are asking the question of what is the best way to oxygenate water, then I would say that circulation/water flow is the most important. Having said that I think your point is a close #2.

The reason I order it this way is because if you could control waste to the best of your ability, but had zero circulation, I think you could potentially end up with an oxygen problem (of course depending on a lot of factors). However, if you have good circulation and poor waste management, I guarantee that most of the time you would be fine.

I am basing that last sentence on what seems to be the philosophy of the majority on this site - and I am assuming that the people who come to this site are probably in the top 20% of fishowners in terms of their care and knowledge. The overwhelming philosophy - from what I have seen is: "10x water flow, water changes every so often, and clean your filter once in a while". The emphasis has been placed on circulation/water flow. While I disagree with this methodology on some points, it seems to work for the majority of people.

Having said that, the connection of oxygenation and water flow is very significant. And unless you are pumping pure O2 into your water, I am not sure what other connection can be made to oxygenation. This is the whole premise behind the superiority of wet/dry filters. I would be shocked to see someone with a wet/dry using something like a bubble wand to provide better oxygenation.

And that just made me think of another point. Oxygenation is not only important for fish respiration, but also for the nitrogen cycle. The assumption behind the supremacy of wet/dry when it comes to bio filtration is that the bacteria thrive in the open O2 environment. So a well functioning system with at least adequate bio-filtration must be sufficiently oxygenated. So I would also say that, as a test, if you are not having a problem with ammonia or nitrites, then you do not have a dissolved oxygen problem.

I still cannot move past my position that based on what I have seen, dissolved oxygen does not appear to be a problem for the majority of fish owners. And in my mind extensively adequate water flow is the reason.


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## boredatwork

lloyd said:


> the key role of water circulation, is to assure the majority of waste is collected into our filtration devices.


One more small point. This is a peeve of mine. Waste is waste no matter if it is in your tank or in your filter. While it looks nicer hidden somewhere you can see it, just because you move it form one place to another doesn't make it any less toxic.


----------



## Toby_H

I think a few of us slowed down just to assure that this is a discussion, not an argumentâ€¦

I completely agree with BoredAtWork that these more in-depth conversations are far more stimulating/entertaining to me. I think far to many people want to know _what to do_ without ever truly learning _why they are doing it_.

BoredAtWork... if there is something you feel that many people blindly accept as a rule... which you feel is unnecessary or improperly perceived... I encourage you to fee free to bring it up. Challenges to some of the assumed habits of fish keeping tend to be some of the most informative threads (in my opinion)

But back to Oxygenation...

I agree that water movement is more important than limiting bioload...

A tank with excessive waste and high water movement will suffer from a handful of problems, but a lack of oxygen likely isn't one of them... but a tank with zero bio-waste and zero water movement will likely suffer from a lack of dissolved oxygen...

Earlier I said



Toby_H said:


> I think we can confuse ourselves and start goofing up if we narrow our focus too much. Stepping back and viewing 'the big picture' gives us a better perspective...


Because Iâ€™ve found that â€œoxygenating the waterâ€


----------



## lloyd

boredatwork said:


> *lloyd* I would disagree about your point #1. I think if you are asking the question of what is the best way to oxygenate water, then I would say that circulation/water flow is the most important. Having said that I think your point is a close #2.


 i consider coming into a conversation on page 4, with a #2 point, a compliment. so thanks.



boredatwork said:


> The reason I order it this way is because if you could control waste to the best of your ability, but had zero circulation, I think you could potentially end up with an oxygen problem (of course depending on a lot of factors). However, if you have good circulation and poor waste management, I guarantee that most of the time you would be fine.


 here is where we start to split. back in the day, we stocked our aquarium with a 'so many fish inch per square foot of surface area' rule. then came the introduction of power filters, and overstocking became the norm. zero circulation was not an issue, so long as we restricted our stocking tendencies. the big evil then, was accumulation of waste. not so much for fear of nitrates, but because decaying waste requires oxygen consumption by bacteria, and we wanted more fish.



boredatwork said:


> ...The overwhelming philosophy - from what I have seen is: "10x water flow, water changes every so often, and clean your filter once in a while". The emphasis has been placed on circulation/water flow. While I disagree with this methodology on some points, it seems to work for the majority of people.


 and here we agree. sort of...flow rate, IMO, is to assure detritus is collected where we want it. water changes are for diluting nitrate. but cleaning the filter is directly relevant to oxygenation, because that process removes excessive organisms reliant on d.o.



boredatwork said:


> Having said that, the connection of oxygenation and water flow is very significant. And unless you are pumping pure O2 into your water, I am not sure what other connection can be made to oxygenation. This is the whole premise behind the superiority of wet/dry filters. I would be shocked to see someone with a wet/dry using something like a bubble wand to provide better oxygenation.


 all i can add here, is that water circulation has little direct affect on oxygen uptake, unless it coincidentally increases the surface area at the same time. wet/dry filters accomplish that better than most any other filtration devices.



boredatwork said:


> ...Oxygenation is not only important for fish respiration, but also for the nitrogen cycle. ..So I would also say that, as a test, if you are not having a problem with ammonia or nitrites, then you do not have a dissolved oxygen problem.


and then we spit again. lol. it is possible for an aquarium to have much more decay present than is necessary to maintain a basic waste cycle. this is why i mention nitrate levels as relevant to d.o. levels. if a keeper is having difficulty maintaining low nitrate levels, it is safe to assume a very active bacterial colony, which in turn, is weighing heavily on oxygen levels. 
in close, and i want to thank you for renewing this conversation, there are two methods important to maintaining oxygenation levels. one, is to increase the surface area where the process takes effect. this can be done with spray bars, wave makers, bubble blowers, larger filtration devices, etc. the problem with this reliance, however, is that availability is constantly in debt to demand. the other method, similar to submarine life, is to limit demand, by eliminating unnecessary debt. IMHO, and thanks again.


----------



## lloyd

Toby_H said:


> A tank with excessive waste and high water movement will suffer from a handful of problems, but a lack of oxygen likely isn't one of them... but a tank with zero bio-waste and zero water movement will likely suffer from a lack of dissolved oxygen...


 right. and sort of wrong. water movement will accommodate overstocking an area. but still water will not become oxygen deplete, unless it is also overstocked. IMO.


----------



## Toby_H

lloyd said:


> right. and sort of wrong. water movement will accommodate overstocking an area. but still water will not become oxygen deplete, unless it is also overstocked. IMO.


But if there is literally zero water movement... and assuming no other form of oxygenation (plants, etc)... then one guppy fry is "overstocked" as it will eventually use up all the available dissolved oxygen... and the surface tension at the surface will not be broken allowing additional oxygen to enter the water...

But flip the equation... tons of fish and tons of circulation w/ surface agitation... there will be plenty of dissolved oxygen available to the fish and the problem will be accumulated waste, not lack of oxygen...

Therefore I would agree that circulation w surface agitation is the primary key to proper oxygenationâ€¦

But someone else could argue that heavy planting is the keyâ€¦ as heavily planted tanks do not require surface agitation and plants can actually reach the â€œover saturationâ€


----------



## lloyd

Cento said:


> ...It certainly wasn't my intent to start a "heated" debate, so sorry for any damage done by that. However, like I said, I got some pretty good advice on how to achieve what I was looking for; went ahead and put it into practice, and now things are peachy keen in my aquaria


IMO, heat cooks debate nicely. anyone who reads your post, will have gained helpful knowledge, all while politely entertained with poignant dialogue. thanks to you for that.


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## lloyd

Toby_H said:


> But if there is literally zero water movement... and assuming no other form of oxygenation (plants, etc)... then one guppy fry is "overstocked" as it will eventually use up all the available dissolved oxygen... and the surface tension at the surface will not be broken allowing additional oxygen to enter the water...


 is the surface tension of a flat surface of water strong enough to deny all oxygen uptake? if it is...then i am wrong on many points... :?


----------



## Toby_H

lloyd said:


> is the surface tension of a flat surface of water strong enough to deny all oxygen uptake? if it is...then i am wrong on many points... :?


I have always thought that between the olils that we commonly see moving around at the undisturbed surface (from fish food) and the surface tension itself... there was no oxygen exchange at the surface... it wasn't until the surface was "broken" via agitation of some sort that oxygenation was able to take place...

But conversation suich as this are the places where such beliefs get challenged...

I can't say I "know" it to be true... only "I think" it to be true...

I'll play with Wikipedia & google for a few and see if I can come up with anything... If you or anyone else have related links feel free to feed the discussion...


----------



## Number6

*boredatwork*
I find your points interesting... but what would you use to explain a tank with NO filter, a completely closed glass lid where the water touched it and the only water movement/ oxygenation came from wooden airstones running into the tank through a drilled hole and another drilled hole out?

Oxygen levels hovered around 8 to 9ppm (salifert)...

oxygenation came from... ?

Lloyd, waste removal was every other day via a turkey baster. :wink:


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## Cento

So, I got bored and I'm back...  Dealing with different problems now, but that a different kettle of fish.. (pun intended). 

Just thought I'd thorw this in, don't think it was mentioned, and maybe i should of wiki'ed it first, but what about evaporation? Won't it slowly break up the meniscus? Or even more, will evaporation in itself, slightly "oxygenate" the water?

And, on a separate line of thought, one refered to earlier about nearly completely stagnant water, this like was kinda interesting... found it yesterday..
http://www.pnas.org/content/102/7/2277.full


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## Toby_H

> Does â€œsurface tensionâ€


----------



## KaiserSousay

> Iâ€™ve read science until my brain hurts


 :lol: 
Luckily, my heads only purpose seems to be keeping my hat off of my shoulders.  
A whole lot of reading, and a bit of comprehension  ..has certainly brought the benefits of wet/dry filtration to light. 
The massive expanse of surface area addition, of even a small scale system can be understood in a new way. 
The continual movement of, whatever scale, of water through the various media allows the tank an ability to "take a deep breath". 
Specially, the heavily planted tank, benefits from this added area during the night, when the plants become consumers of oxygen, instead of producers. 
With this system we not just replicate wind/wave action, but add to it. 
If I keep reading, I`m going to talk my way right into digging all my sump stuff back out  
It still seems to me, the major factor is water movement. 
Not dismissing temp. or ph, for they play a mighty role in the process. 
It is the movement of available surface area that provides the exchange environment.


----------



## lloyd

the term 'hypoxia' was instrumental in helping me to affirm my opinion. here's a link to an easy read on the topic: 
http://books.google.ca/books?id=SAdDtT7 ... um&f=false

there is mention that ice is capable of preventing oxygen diffusion. but no mention of 'still water' being as deadly.


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## Toby_H

I think I'm ready to admit I was wrong Lloyd... I've started to believe that surface tension is not enough to completely prohibit gaseous exchange...

My girlfriend, who works in a Chemistry Lab at a local Univ... works with "deoxygenated water" sometimes and has done tests/esperiments monitoring it's oxygen levels (even did one experiment/test a couple years back with fish, but doesn't remember much detail).

She says as soon as the seal on "deoxygenated' water is broken, it starts taking on oxygen (despite surface tension). Although she said if left idle (not disturbing surface tension), it will take on air/oxygen far slower than agitated water... and will not reach it's true equalibrium... or saturation point...

So surface tension does impede oxygenation of water... but does not prevent...

I also acknowledge that my response to Number 6's question was in conflict with what I was suggesting about water tension. For bubbles under water to be viable "surface area" available for a gaseous exchange, this exchange would have to be able to take place through surface tension (which is even higher in bubbles as they have the presure of water further condensing the surface tension).

Yet another thing I've learned by participating in these conversations that are to a degree "over my head"...

I also gained a better perspective about water in general on a molecular level and how why it bonds to itself, how/why it bonds with other free elements (such as O2) as well as many details about surface tension...

Heck if even taught me why free oxygen is O2 and not just O...

Thanks Cento for gettin gthis ball rolling... thanks to everyone who has put up with my participation


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## lloyd

yea.. i had fun too. thanks cento. =D>


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## Cento

Ha! I was the one who needed the lesson! :lol: Thanks guys for all your replies!

Its nice to have a resource like this to get information at this level. IMO, its far better then any book written by PhD guys, who you don't know from Adam, giving you instruction thats probably 3/4 based on theory. At least here, you get it straight from the horses mouth (not calling any of you horses), and you know that there are years (sometimes decades) of experience and "real-life" practical testing behind opinions and theories.

Thanks again!


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## Toby_H

Funny...

While this conversation did take place amongst hobbyists... for it to reach the level this one did, I think many/most of us had to reach well beyond our experience and look some things up in the articles & books written by those PHD'ed people.

There are a lot of things that I've learned through experience that work very well for me. But it takes my understanding to a whole new level to read about the science behind it to understnad *why* it works for me...

And understanding the why's is where those PHD'ed folks come in handy...

So in the end... the balance is where it's at... knowledge without practical application is wasted potential... application without knowledge is like Peeing in the wind... (ya just hope and pray ya don't end up wet)...

Like with most things in life... the solution is in the balance...  coming from a guy who has a PHD in obsession & compulsion


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## boredatwork

Man, I missed out on a lot. I hope you all didn't think this discussion was over?

OK - first - I think I need to go back a couple pages (hey, you must admit, moving linearly through time and threads is so ... ordinary...)

*lloyd*, to me, the example of a hyper-over-over-stocked goldfish tanks is irrelevant. Maybe not irrelevant to the discussion but irrelevant to my point. I would say it is unfair to use that example. Not unfair because its a bad example, but because I would consider that a data outlier. That is definitely not a 3 sigma example. My point is that for the average tank with a common setup, even if it is "over"stocked you will not have a problem with oxygenation. Again, if that assumption is wrong then no one would keep fish because they would die to easily.

Now, to *Number6*, I am glad you asked that question. This makes me happy to know that people are disagreeing with my poor explanation skills as opposed to what I am trying to say. (Although when posts are as long as mine, I doubt anyone really reads the whole thing - heck, even I wouldn't).

I do not want to say that bubble devices do not oxygenate a tank. I forget if it was this thread or another where I said that an aeration stone will provide a slight boost in DO. Still water at room temperature has about 6ppm of DO while in the experiments I have seen an oxygenation stone boosted it to about 10ppm. Now, I am pretty sure those were not sealed off tank, but after thinking about it, they were probably pretty close to it. And, actually, I have never repeated the trite explanation of why bubbles do not add oxygen to water. So...I am not saying bubbles do not oxygenate water.

My point is that if you took that tank in your example, lifted the lid at least a 1/2 inch off the water surface and put in some (any) kind of power filter, that filter would be able to provide more oxygen than the bubble device - thereby rendering the bubble device useless. To me, that is the bare minimum oxygenation implementation of probably 98% of hobbyist tanks out there. Because of that I will still say that oxygenation is not a problem that people really need to think about. Now, if you have 100 goldfish in a 10 gallon tank, that's a whole other post.

Now I am going to catch up on some of the other posts and provided links. I will, of course, provide any comment to those if I come up with any.


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## boredatwork

OK, I'm caught up.

A few points, and I don't know who I am responding to because I didn't keep track of who said what.

This is kind of off topic, but someone mentioned water flow being essential for moving detritus. I have always disagreed with this. To me, waste is waste no mater where it is. Whether it is on the substrate, on a rock, floating in the water, or firmly lodged in the filter, it is decaying and therefore toxic. Moving detritus out of the way is only useful for easy cleanup or making things look nice. A fish tank needs to be thought of as a water system, not just a fish tank. The water system includes everything that holds water - normally the tank _and_ the filter. The only way to remove the toxicity of detritus is to remove it from the water system - not just the display tank.

Somewhat related to that is the various definitions of water flow/circulation. In general its a well understand definition, but after a few posts in the thread I was using the short hand of these few words to refer to water flow that both disturbs the surface of the water and also can eventually distribute oxygenated water from the surface throughout the tank. I agree the you could come up with example of water flow that do not aid oxygenation - I was assuming that at least in this discussion that is a known bad option.

As to surface tension, oxygenation, and DO utilization I don't think there have been any scientific breakthroughs in this thread, but I will recount one story.

Four years ago I had a decorative bowl of water (approx 1 gallon) with a plastic plant and marbles on the bottom. In the bowl were 3 small guppies and one of those african frogs you can buy at Petco. I know what everyone is thinking, but it was technically not my tank/idea, but my wife's (although she put in zero effort to keep those fish alive - btw, whose third generation incestuous offspring are still alive in one of my tanks to this day). After the first few days of being set up the fish were obviously having some trouble breathing. They were always at the surface of the water sucking for air. After realizing this was potentially a life or death situation I went out an bought a small air pump and aeration stone. I cleverly installed the air tubing so that it was inconspicuous (except for the bubbles obviously). Within 24 hours the fish were swimming around just fine. Except for a one death, and a concurrent lesson learned about male/female behavior, those fish and all future replacements lived in that bowl for two years with any problems. The only other type of oxygenation was a weekly water change (probably about 80%).

I forget what my point was, so I will just draw some quick conclusions. Oxygenation can easily be a problem in standing water. A little water surface movement and sufficient circulation is enough to cure the problem. Like the million goldfish example, I would say my crappy guppy bowl, while probably extremely common, is also not a good example, but I still consider it is a good lesson.


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## lloyd

boredatwork said:


> This is kind of off topic, but someone mentioned water flow being essential for moving detritus. I have always disagreed with this. To me, waste is waste no mater where it is.


 welcome back to the discussion. and that 'someone' was me. my assumption, is that waste collected into filtration equals waste removed. and waste removed equals less bacterial activities hoarding oxygen 24/7. your disagreement implies a filter is never cleaned.
please do not assume, that because i quote your points, i am opposed to all of them. i simply disagree that the answer to oxygenation lies in non complacency. IMO, all life within an aquarium is on artificial respiration. remove the machine...and death is imminent. so i find it rather simplistic, to suggest agitation is the answer to this post (even though it truly is), without more argument about what, when, where, how, and how much. i've achieved my goal here.


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## Toby_H

When we look at the bare question that titles this threadâ€¦



> Whatâ€™s the best way to oxygenated your water?


I think the answer would be a proper balance of lower temperature, surface agitation, ample water movement/distribution, heavily planted, minimally stocked, well cleaned, etc, etcâ€¦

But there is a gulf of difference between â€œbestâ€


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## KaiserSousay

The one example, sealed tank, that when exposed to atmosphere began an oxygenisation(is that a real word  ) when the seal was broken, blew my mind..I would have sworn, without movement, that would not be possible. Would certainly explain the benefits of the large footprint tank, over the same volume tall. Would also suggest the transfer of BAW`s guppies to a bowl with ever larger footprint vessels would have helped his wifes` incestuous shoal. :lol: 
That makes me look at the spillway of the average HOB in a different light,more of an extension of available surface area in the same footprint....or am I off target here?


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## nick a

No you are on target. 
But, its not so much the 'spillway' as the ripples/waves created by the mechanically powered current.

A 40BR has 648 sq in of surface area. Adding just a 1/4" of ripple across that surface can expand it to over 750 sq in. (using funky math & lot's of assumptions on constancy of ripples etc...--but you get the point).

Further enhancement is derived from the current's ability to 'roll' the water from top levels to bottom--thereby keeping the oxygen diffusion cycle working efficiently and the tank healthy.

All of which an airstone does. It's a matter of degree--not of kind. Terms like "best" are fine for narrowly defined topics. I consider an airstone in a sponge filter to be the 'best' for my fry tanks--but not for my 125s

We are in some part replacing the function of natural forces not present in our home aquariums. For example, the wind which creates waves in lakes. Remember that colder water has greater surface tension? Perhaps, in colder waters, greater surface tension allows for larger waves to be generated = more surface area+ more distribution=more DO........


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## Toby_H

Nick... I feel ya on the funky math full of assumptions calculating the volume of a disturbed surface...

And I completely agree with you on the fact the word "best" is too loose of a word to be using in this discussion to do extreme variables in different situations...

KaiserSousay, I agree with you that the additional surface area of an HOB is helpful...

I also would suggest that this highly oxygenated water is very beneficial to our 'Beneficial Bacteria'... despite the common belief (or misbelief?) that HOBs are "mainly for mechanical"...

Oxygenate - http://dictionary.reference.com/browse/oxygenate

I doubted it to when I first engaged in this type of conversation


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## boredatwork

lloyd said:


> welcome back to the discussion. and that 'someone' was me. my assumption, is that waste collected into filtration equals waste removed. and waste removed equals less bacterial activities hoarding oxygen 24/7. your disagreement implies a filter is never cleaned.
> please do not assume, that because i quote your points, i am opposed to all of them. i simply disagree that the answer to oxygenation lies in non complacency. IMO, all life within an aquarium is on artificial respiration. remove the machine...and death is imminent. so i find it rather simplistic, to suggest agitation is the answer to this post (even though it truly is), without more argument about what, when, where, how, and how much. i've achieved my goal here.


I am not exactly sure what a lot of that means, and to that end I may be misinterpreting a little.

This is a little off topic, but I am not sure why you think that if the waste is moved into the filter that it is "removed". I still disagree with that kind of thinking. Waste is not removed until you take it out of the water system. Whether the waste is in the tank or in the filter it is still using up oxygen as it deteriorates. I don't want to say the filter is never clean, just that it is not clean until you clean it. Just because waste is moved into a filter doesn't mean the water system has been cleaned from the waste, but that the waste has been moved. There are actually some people that design their tank to avoid waste being sucked into the filter. This way you provide a cleaner environment for your beneficial bacteria. The waste is kept in the display tank and vacuumed out.

As for the point about non complacency and agitation I am confused. I am not suggesting complacency. Using a filter to provide the respiration you speak of is the opposite of complacency. I don't want to be understood as saying you don't need a filter? And I think to that end there was much discussion about how and why an adequate filtration system will provide all you need for good, best, or adequate oxygenation.


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## Toby_H

boredatwork said:


> I am not sure why you think that if the waste is moved into the filter that it is "removed". I still disagree with that kind of thinking.


Iâ€™m pretty sure his point is people clean their filtersâ€¦ so he accounts for waste collected by the filter is waste that will be soon removed by the keeper of the aquarium, when they clean the filter regularlyâ€¦

I personally tend to agree with Lloydâ€™s thinking on that pointâ€¦ as I use mainly HOB filters and one of the reasons why is the ease of cleaning themâ€¦

Yet I know plenty of canister users who do not clean their filters often at allâ€¦ and in this application I would agree with BoredAtWork, that they should avoid picking up waste in filters that are not going to be cleaned fairly frequentlyâ€¦

Different strokes for different folksâ€¦

Yet another point that no single answer is â€œthe bestâ€


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## Cento

I'd like to find out what takes up, or consumes, more oxygen; Fish, or bacteria? pound for pound, I'd think it would be the fish, but I've had my share of surprises in researching this kinda stuff...

Lets say for instance, a 55 gal, with 15 fish, about 4" in size, and a canister filter like say, an EHEIM 2213. And it is well maintained and well established. Setup for 2 years lets say, so as much bacteria as this aquarium will ever be able to support. So, regardless of how well oxygenated it is, more of interest is which one consumes more oxygen. It would lead me to another lingering question; is there such a thing as too much bacteria?


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## lloyd

Toby_H said:


> boredatwork said:
> 
> 
> 
> I am not sure why you think that if the waste is moved into the filter that it is "removed". I still disagree with that kind of thinking.
> 
> 
> 
> Iâ€™m pretty sure his point is people clean their filtersâ€¦ so he accounts for waste collected by the filter is waste that will be soon removed by the keeper of the aquarium, when they clean the filter regularlyâ€¦
Click to expand...

 yes. and thanks Toby_H. and more to the point of this post: filtration devices, specifically those set up to perform mechanical duties, store waste in a way that limits aerobic opportunism within that particular area. so IMO, filtration collection slows aerobic activity, and that equals less demand for oxygen within the system.
the system only fails in this regard two ways. and both concern water movement: 1) when filtration devices are ignored to the point of bypass, or 2) if water movement is not adequate to keep wastes turbid until collection is achieved. then, aerobic activity begins to increase within the open areas, and oxygen demand soars accordingly. hence, the need to include nitrate levels, along side of water movement, into the oxygenation issue. :fish:


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## Toby_H

Cento said:


> I'd like to find out what takes up, or consumes, more oxygen; Fish, or bacteria? pound for pound, I'd think it would be the fish, but I've had my share of surprises in researching this kinda stuff...
> 
> Lets say for instance, a 55 gal, with 15 fish, about 4" in size, and a canister filter like say, an EHEIM 2213. And it is well maintained and well established. Setup for 2 years lets say, so as much bacteria as this aquarium will ever be able to support. So, regardless of how well oxygenated it is, more of interest is which one consumes more oxygen. It would lead me to another lingering question; is there such a thing as too much bacteria?


So your not really asking pound for pound...

More so asking the quantity of bacteria to process the ammonia of a 1 pound fish... vs a 1 pound fish...

I'd speculate that the fish would by a long shot... but I'd have to admit that is only speculation...

How would you test it? You would have to some how control / regulate the introduction of oxygen into the system... which is over my head...

When talking this stuff with my girlfriend (who works in a chemistry lab at a local Univ) she has made it sound like the bacteria use very little oxygen compared to fish... but I've never asked the question directly... I'll ask her tomorrow and tell her you guys don't believe her so she'll need reference links (shhh... I want to see them too, but I it sounds like I don't believe her it'll cost me an expensive dinner).


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## Cento

Ha! Dinners!? Thats nothing compared to the price of roses! Have you bought a dozen quality roses lately? Insane!!! :lol:

Yeah, I would think it would be a very difficult experiment to control. Especially if you were to test it as a "real life" aquarium; with all the gravel, rocks and filter media. You'd have to keep track of all the bacteria... that would be tough... Let us know what she says...


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## lloyd

Cento said:


> I'd like to find out what takes up, or consumes, more oxygen; Fish, or bacteria? pound for pound, I'd think it would be the fish, but I've had my share of surprises in researching this kinda stuff... It would lead me to another lingering question; is there such a thing as too much bacteria?


http://www.bioconlabs.com/oxy.html
http://edis.ifas.ufl.edu/FA002

( i still want to hear what Toby_H has to offer, and hope he gets to eat...


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## Cento

Hey Lloyd, thanks for the links... They both were very interesting... I enjoyed the second one the most even though it had more to do with ponds and fish farmers..

But interesting to know that this "oxygenation" issue is of great importance to fish farmers. Thats something I didn't think of. Imagine loosing a whole crop (or school or heard or whatever) of fish overnight just becuase of lack of oxygen?! Imagine a beef farmer finding 1000 cows dead the next morning?


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## Toby_H

Lloyd your awesome... has anyone said that in this thread yet? We should have...

So that says a fish uses about 4 times the amount of oxygen as the bacteria that it takes to convert it's waste into nitrates...

It also says that 1 ounce of fish creates 1 milligram of ammonia... I've heard a few people say they wondered about this number... sure the exact accuracy is questionable due to variables, but it's somewhere to start...

It also states : Air stones are by far the least expensive and the most efficient way to aerate an aquarium... Volunteers to debate this?... lol

Great article... I want to repost and comment on most of it! But I won't........



> Can you really visualize just how tiny 7 parts per million is?


One ounce compared to 1,116.5 gallons... is 7ppm...

PS - I just got off the phone with my girl... and she said that she would think that the bacteria use far less than 1/4 the DO as fish... although without having a true idea of the volume of bacteria she is considering it is hard to estimate... although I did give her the numbers quoted above...


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## KaiserSousay

> consumes, more oxygen; Fish, or bacteria? pound for pound,


Funny, at first reading, my thought was bacteria. No science to back it up. Just a gut reaction..might have been the picture of a pound of bacteria I conjured in my minds eye.
The Blob, coming after Steve McQeen :lol: 


> is there such a thing as too much bacteria?


No..do not believe that could happen, long term. When you get a bloom, it is just a reaction to a change in the food-feeder balance. Once balance is regained, there will only be enough to consume the available food. But, you already knew that..just one part of your brain spitting questions out faster than the other part can answer.


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## rwolff

hmm...interesting
i use an air pump, without the air stone, it just gives big bubbles for my red devil tank. Helps circulate the water way better then the HOB to clean up waste laying around/debris. And I'm very lazy to vacuum, esp since it has sand..uff..not to mention the attacks i get from the red devil. So id say i have/use it more to help circulate the water.

i once lost a BIG catfish, due to depleted oxygen i guess. power went out for a long time and i guess the catfish uses more oxygen then the water can exchange O2 for. So it got overly stressed by fatigue and/or suffocated? Anyway, since the big catfish incident, i never overstock nor go light with circulation.

'Cause water would hold CO2 and O2. Does water try to a keep a balance of these two? or it just exchanges whatever is available on the surface? and does with/ other particals (salt/minerals, N, metals, other gases, etc) have effects on the oxygen exchange..how much 'space' would it take of of them or does other particals go by different rules in water? That's what exchange is all about, something must go out for something to go in, imo. 
Cause air does not only consists of O2 and CO2 alone either. So my thought is of all 'airexchange' only a percentage of it is O2...and if overoxigenated, then it would release 'excess' O2 also in the air by the surface (i read a post about that, about oxygenating with pure oxygen to 20 ppm or something like that and then when stopped, it would go bk to 4ppm or so). How much % of O2 gets exchanged of all the other stuff in the 100% that gets exchanged?

Another thought, if air exchange is at the surface, and everything is lid, hood, HOB and so on... does it make a difference the kind of air stuck in there that gets exchange bk into the water, or is this at a minimal that it doesn't matter?

So overkill with O2 without a use for it (by fish) seems pointless also. I know we shouldn't worry about these much, but I'm interested now.
I kind of have more questions...but my left and right brain are clashing right now, i cant bring them into words. 
Dunno if anyone would care to help me out with some answer. hehe.


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## Cento

Well to answer at least one of your questions, I know for a fact that salinity (salt content) has an effect on how much oxygen water can hold. Freash water can hold more oxygen then saltwater. I think its only slightly at the same temps, but that varies when you're talking drastic temperature changes..

As for CO2, i believe water is more concerned with oxygen, since oxygen and water are inexorably tied molecularly. It tends to work itself or make itself available for oxygen, but I don't believe that is the case with CO2..


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## lloyd

rwolff said:


> Another thought, if air exchange is at the surface, and everything is lid, hood, HOB and so on... does it make a difference the kind of air stuck in there that gets exchange bk into the water, or is this at a minimal that it doesn't matter?


 i've worked this one over a few times in my head, and my personal conclusion, is that tank covers have minimal interference with dissipation. unless...you experience excessive condensation on the underside of the glass. that would indicate an (unnecessary) increase of water temperature, which is relevant to the topic here.


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## Toby_H

> 'Cause water would hold CO2 and O2. Does water try to a keep a balance of these two? or it just exchanges whatever is available on the surface? and does with/ other particals (salt/minerals, N, metals, other gases, etc) have effects on the oxygen exchange..how much 'space' would it take of of them or does other particals go by different rules in water? That's what exchange is all about, something must go out for something to go in, imo.
> Cause air does not only consists of O2 and CO2 alone either. So my thought is of all 'airexchange' only a percentage of it is O2...and if overoxigenated, then it would release 'excess' O2 also in the air by the surface (i read a post about that, about oxygenating with pure oxygen to 20 ppm or something like that and then when stopped, it would go bk to 4ppm or so). How much % of O2 gets exchanged of all the other stuff in the 100% that gets exchanged?
> 
> Another thought, if air exchange is at the surface, and everything is lid, hood, HOB and so on... does it make a difference the kind of air stuck in there that gets exchange bk into the water, or is this at a minimal that it doesn't matter?


Lots of questionâ€¦ and some good ones 

Iâ€™ve read several articles describing how water will seek an equilibrium point of O2, but never have read it mentioned that CO2 has any influence on that equilibriumâ€¦

As Cento mentioned, salt water holds less oxygen than fresh, but Iâ€™ve never read anything mentioning TDS (total dissolved solids), PH, or gases to have an influenceâ€¦

There are lots of gases/things in air that are not readily â€˜absorbedâ€™ by airâ€¦ although some may settle on the surface and then be mixed inâ€¦

You are correct in that if water is pushed to over saturate, it will begin releasing O2 into the air. It has a state of equilibrium is seeks to achieve and will give or take oxygen to achieve this point.

Air quality at the surface is a great point! As most of us have a very tiny volume of air between our water and glass tops. Does warm air have a lower O2 level than cool air (like water does)? Does humidity reduce O2 levels in air? I would have to imagine that, like water, air has an equilibrium of O2 and other gases it seeks. If the air is deprived of oxygen will it â€˜suckâ€™ O2 out of water that is at equilibrium?

It makes complete sense to me that the quality of air available at the air-water interface would make a difference, yet I have not read any details on this matter.

I continually read that â€œtemperature, salinity and elevation (air density/pressure)â€


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## lloyd

the only relevance, i can find to oxygenation and TDS, is when photosynthesis is part of the equation. turbidity slows photosynthesis by blocking light.
as for the air-water interface issue: we top fish bags with oxygen, prior to shipping, for this very benefit.
page 7??...geez, i need a job... :lol:


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## Cento

Ha, you and me both! :lol:

I forgot about the issue of oxygen density in cold/hot air... I know for sure that cooler air is denser then hot air, becuase that is part of the reason for a cold-air intake for your tuner car (toyota, honda, kia.. ha!). The cold air contains more oxygen, therefore more power for your car (I know its more complex then that, but i can focus on only one thing at a time).

But that is in the case of a car with extremely hot air in the engine compartment in relation to the cooler air outside the car.. probably no where near the difference between outside of the aquarium lid and inside.

Thats concerning temp. But as far as how much air "trapped" under the lid has been drained of oxygen.... well, I'd like to know that too!


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## Toby_H

Cento said:


> But that is in the case of a car with extremely hot air in the engine compartment in relation to the cooler air outside the car.. probably no where near the difference between outside of the aquarium lid and inside.


Since when did we start over looking slight differences... We've been splitting hairs since page 2


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## boredatwork

There was an equally long thread on this topic a while back and I made a response at about this point in the conversation, and essentially got yelled at for asking such a question. Knowing that, let me ask it again.

First, I want to say that I still find all of this information interesting. However, I also feel that discussing this level of information without any expertise in these areas makes me feel like a fish out of water. But it is still interesting.

Now, for the big question. Why does any of this matter? I would say that the amount of effort expended discussing and researching has gone above and beyond the significance of this topics usefulness, at least in the hobbyists realm. And let me try to be clear. I am not asking this question in the sense of "this is a useless topic so what is the point?", but in the sense of, "OK after all this information and discussion, what is the takeaway?".

I hope that was clear.


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## lloyd

boredatwork said:


> ...Why does any of this matter?


 1 ) you know the risks of increasing stock loads.
2 ) you know what to do when the power goes out.
3 ) you know what cloudy water means.
4 ) you know why your fish are not maturing as fast as the other guys.
5 ) you know what likely killed a fish that died with it's mouth gaped open. 
6) you know how to not kill every fish in a bucket.
7 ) you know why your pleco is living in the filter exhaust tube.
8 ) you know how to read through the b.s. of filter advertising.
9 ) you know how to transport fish more safely.
10) you know where to fish a lake to actually catch one. 
11) you know your better than average.


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## CharlieTuna

i too got away from air stones. after i switched from hob's to cans i did some research and found that i could break the water serface if i angled my canister return outlet on a 45 degree angle facing up and i attached a hagen surface skimmer (not protine skimmer) to the intake to clear up the surface scum. I could get away with angling the return upward as i also had a under gravel jet system to push the poo twords the canister intake. so i wasn't relying on the return outlet to provide the only current in the tank.


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## lloyd

CharlieTuna said:


> i too got away from air stones. after i switched from hob's to cans i did some research and found that i could break the water serface if i angled my canister return outlet on a 45 degree angle facing up and i attached a hagen surface skimmer (not protine skimmer) to the intake to clear up the surface scum. I could get away with angling the return upward as i also had a under gravel jet system to push the poo twords the canister intake. so i wasn't relying on the return outlet to provide the only current in the tank.


 good point. i overlooked that one:
12) you know how to set up your equipment properly.


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## Toby_H

boredatwork said:


> Now, for the big question. Why does any of this matter? I would say that the amount of effort expended discussing and researching has gone above and beyond the significance of this topics usefulness, at least in the hobbyists realm. And let me try to be clear. I am not asking this question in the sense of "this is a useless topic so what is the point?", but in the sense of, "OK after all this information and discussion, what is the takeaway?".


I completely agree that we have long ago surpassed the point of what your average hobbyist needs to knowâ€¦

I have continued to participate in the conversation because I enjoy learning new thingsâ€¦

I feel that the more thorough our understanding of our aquariums eco system works, the more efficient we can alter our system to best serve our systems needsâ€¦ as well as to create efficient â€˜back upâ€™ systems in case something fails or requires changing.

Over the course of this conversation I have looked up many things that have fed other tangents of learning.

I truly hope this â€œin-depthâ€


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## lloyd

Toby_H said:


> I completely agree that we have long ago surpassed the point of what your average hobbyist needs to know


 i disagree. every person who follows, and comprehends this conversation, will be able to help here: http://www.cichlid-forum.com/phpBB/viewforum.php?f=23
and most keepers already there, would likely answer many of their questions within this read. IMHO.


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## cjacob316

what about one of those fans i've seen instead of a powerhead, looks like a torpedo, i've seen it used to pushwater around, i don't want to create too much current in my tank, but I don't like the spray bar, too much visible equipment


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## rwolff

ok, cool..tnx for the answers, hehe...i am just interested in how things work around O2 and so on.
I like to know/have an understanding on how things go about.
I just realized that my air pump just brings new air to the top under the lid, so its a good thing it makes it a bit drafty under there.

...i enjoyed this thread.


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