# HOBs for aeration



## mclaren880 (May 20, 2012)

I'm wondering how much aeration Emperor 350/400 and AC110s provide a tank.

I recently set up a 125 gallon all male (will be moderately to heavily stocked) peacock/hap tank, and i'm using my fx5 output nozzles to point at a downward angle to provide current in the tank (I'm trying to avoid buying powerheads by using my current equipment). I have an emperor 400 on it along with an penguin 200 on it to provide some surface agitation. Preferably i'd like to replace the 400 with an AC10 and not run the 200 at all. Would a single AC10 provide enough surface tension for a tank of this size? Or if i'm not using the fx5 for surface agitation, do i need to be running two HOBs (one on either side of the tank)?

I'm not totally clear i suppose on how the oxygen transfer works.


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## Iggy Newcastle (May 15, 2012)

I've never used a HOB on such a large tank. I do have a 40 breeder filtered by 2 AC70s. Same depth as a 125(18") and they provide excellent surface agitation. I would think an AC110 would be fine, but not for the length of your tank. You'll most likely have a buildup of film on the surface on the opposite side of the 110. Best bet- powerhead or circ pump.


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## mclaren880 (May 20, 2012)

So a circulation pump works for aeration? Is there a general guide to know how much aeration I need? Powerheads don't do as much for surface agitation do they?


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## Iggy Newcastle (May 15, 2012)

Circ pumps will move a lot more water. I have used a brand that mounted to the glass with suction cups. I curse the day I bought them. Never stayed put. Coming home from a vacation to see it laying on the bottom of the tank and all the sand blown to one side was brutal. I invested in some Hydor Koralia Nanos. About $50 on sale. They mount with a magnet. For a 6' tank I would get something that does 1200-1400 gph. Aim it towards the top and at your filter intake side of the tank.

Of course, you could try the 110 first and see how it works out...


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## mclaren880 (May 20, 2012)

Thanks Iggy. I have a Hydor Koralia 800 in my 75 and i have to admit, it's great. Runs problem free 24/7 (so far, at least). Sounds like i might need to suck it up and get a couple more. So you just run a canister and the circulation pumps? Do you have the canister output aimed at the top for surface agitation? Or do you just not worry about about specifically creating surface agitation and circulate the **** out of the water? haha.


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## Iggy Newcastle (May 15, 2012)

I have a 3D background and use the circ pumps behind to keep things moving back there.

When I didn't have the BG I used 2 pumps on opposite ends of the tank. Then I built spray bars for each canister so the pumps were no longer needed.

Each of these tanks were 6' long.


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## mclaren880 (May 20, 2012)

I'd like to build a spray bar, but i don't totally like the idea of putting black paint in the tank and I can't find black PVC. I have the back of the tank painted black so i really don't want to put a white PVC pipe in. Did you just paint them? I've heard of people finding black pvc, but i'm having trouble finding any. I'm thinking of 2 Hydor Koralia 750s, although a spray bar for the FX5 would be ideal, as it would be cheaper.


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## Iggy Newcastle (May 15, 2012)

Krylon Fusion spray paint. Made for plastic and safe in your tank. Just let it cure for a few days.

Before you paint it, assemble everything and test it out. You'll most likely have to modify the spray bar, especially the drilled hole size, until you get the results you want. Only glue the 90s and connections that will be on the outside of the tank. This way you'll be able to swap out bars later on if you need further modifications. I suggest hose clamps on your tubing to plastic connections.


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## mclaren880 (May 20, 2012)

Thanks iggy, so you didn't have to put a clear coat over it or anything? Did you use a needle or something after painting to keep the holes clean. How is the flow from it? Do you think I could skip the hydors with a single spray bar from an fx5?


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## Iggy Newcastle (May 15, 2012)

I did not use a clear coat. Glossy black is what I used, I think.

Didn't have to clean the holes after painting.

I had 2 spray bars for each FX5, at 3' each. The flow was insane. I think if you built a 5' bar and left 6" of space on each side(from spray bar to tank), you'll be good. Start small with your holes. I ended up with smaller holes on the bar inlet, and larger holes towards the end of the bar. You'll have to experiment to get an even flow across the whole length. Hope this makes sense.


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## mclaren880 (May 20, 2012)

Thanks! Sounds like this is going to be my best option.


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## skurj (Oct 30, 2011)

Sneaking into this convo... I am going to be building a 180g shortly and want to do an 2262 (or fx5) with the spray bar running length wise.. (not across the back, have that now on a 55 and don't like it) tank will be 2 ft front to back, if I make the bar out of pvc do I run the risk of the pressure blowing it apart if I do not glue the under water sections? Want to be able to aim the bar if needed.

Oops and the 180g will have at least 1 canister and an ac110 to start probably 2 and the 110 as fish mature (Big Centrals)


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## Iggy Newcastle (May 15, 2012)

So the bar will be around 24"? The depth of the tank?


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## spotmonster (Nov 23, 2006)

Personally, I believe there is a little to much hype over surface agitation. Don't get me wrong, it's needed, but we don't all need to spend good money on 3 extra pumps to accomplish a satisfactory amount of agitation.

I know 100% for sure you will be fine by adding the 110 by itself and the FX5. I'm running the exact items on my 180 with no issues. My FX5 is aimed downward like you propose.

I am also running a 4ft 90 gallon with a FX5, and no other water pumps whatsoever. On this tank I have one jet pointed up at the surface and 1 pointed down. This tank is sealed up at the top very well with that plastic stuff on the back of the glass tops to eliminate as much evaporation as possible.

Note, I do however run an air pump on both of these tanks. Each has 2 airlines per tank, towards the corners. Air lines work nicely to keep water moving in slow area's, without spending extra dough on internal pumps.

A spray bar as Iggy suggested will work well also.

I'll also add, krylon fusion has been used on items in both of these tanks with no issues. Just make sure you let it dry for a few days.


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## skurj (Oct 30, 2011)

Yeah the bar will be close to 2ft. I am considering the 2262 just because the hydor inline fits it easier than the fx5. The 110 will be added for now and as the fish mature the fx5 will be added to take up the slack.. (tho I do have a great price on one lined up so it may go on sooner) I will likely just make a pvc return for the fx5. Tanks is 6 x 2 x 2
Oh yeah I can't stand the noise of an airpump, but this one it maybe considered because some of the fish may potentially be classed as riverine.


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## Deeda (Oct 12, 2012)

The only part of the spray bar that you don't need or want to solvent weld is the section that is actually in the tank. You definitely want to solvent weld the connections that go over the rim of the tank.


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## mclaren880 (May 20, 2012)

spotmonster said:


> Personally, I believe there is a little to much hype over surface agitation. Don't get me wrong, it's needed, but we don't all need to spend good money on 3 extra pumps to accomplish a satisfactory amount of agitation.
> 
> I know 100% for sure you will be fine by adding the 110 by itself and the FX5. I'm running the exact items on my 180 with no issues. My FX5 is aimed downward like you propose.
> 
> ...


Awesome! Thanks Spotmaster! So really, in your 180, only one part of the tank (the part with the ac110) is having it's surface agitated, and the other side has nothing at all?


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## spotmonster (Nov 23, 2006)

In the 180, the surface major agitation occurs in the middle, that's where the AC110 is installed. Near the ends is where I have air lines ran under the sand, so I do get bubbles.

Based on my experience with the 90 gallon, in the future I am going to run 2- FX5's on my 180 and drop the 110. Seal the top like I did with the other tank (with the plastic stuff, not actually "seal it"). And I will probably leave the 2 airlines.


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## SupeDM (Jan 26, 2009)

Sent the origional poster a PM. Not sure of rules regarding specifit talk of equipment. Posting here now to share with forum.

The basics of aeration are not to add oxygen to water. The Idea is to create enough surface agitation to drive off CO2. Water at any specific temperature has a limited ability to hold dissolved gasses. In order to hold more Oxygen we must drive off the CO2 that our fish put into the water Via respiration. Oxygen tends to disolve into water more easily than CO2 there fore if we push out the CO2 and have water moving on the surface of our tanks it will naturaly pick up oxygen. This is the reason that planted tank keepers must push CO2 instead of just agitating the water. Also there are devices made specificly to help CO2 dissolve into water. I will push it a little on the rules here and Say that because of the internal spraybars and biowheels the emp 400 is hands down the king of offgassing CO2 and agitating the water as far as HOBs are concerned. If you would like to test this theory put one on your High Tech planted tank and watch the readings and watch it increase the CO2 output. MY bubble counter was going so fast i couldnt even count them when i had the filter with biowheels on it. Without it is 5-15 per minute depending on time of day and last water change. If i am violating any serious rule with this post please PM me and do what is necessary to fix it.


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