# filterless 1000 gallon tank. Is it possible???



## newguyinillinois (May 1, 2011)

I am planning on building a 1000 gallon plywood in wall tank at tax time. And I am having trouble deciding how I am going to filter the thing. A sump would have to be huge. and i cant find a canister that big. So I was thinking, I live in a town with a set rate on water. No meters. I pay 40 bucks a month every month. So can I just rig up an water changer to do an 100 percent water change every 24 hours? Then I wont need a filter at all rite? That is .70 gallons per minute. Not that much at all. Would be so simple. One small over flow at the water line and one small line running to the bottom of the tank in the opposite corner. Some power heads for current. Simple. Or am I forgetting something????????


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## BillD (May 17, 2005)

It could probably work, but you would need to heat the water and you would not actually get a 100% water change. I suspect that if you did the math there would be a point where you would have a build up of nitrate that might require a larger change. The tank surfaces would become covered with beneficial bacteria that would deal with the ammonia and nitrite and if the bioload was right it should work. The powerheads might actually work against the efficiency of the system by constantly mixing the fresh water with the old. This is the way many trout farms operate, with a continuous flow of fresh water and no filtration.


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## roke28 (Oct 26, 2008)

I wouldn't do 100% water change. Maybe 50% If you change out all your water then your tank will have to cycle all over again. It would be alot of work especially a 1000 gallon tank. I would just get a couple canister filters and save the headache. There are lots of guys that built large tanks on this forum. You should PM them and ask about there filtration setup :thumb:


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## allierw (Apr 20, 2006)

There are pond filters that are more than adequate to filter 1000 gallons...that is the size of my pond and I run 2 canisters with large underwater pumps.


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## fmueller (Jan 11, 2004)

What you propose would definitely work. As BillD pointed out, the surfaces in the tank (substrate, decorations, and so on) would be colonized by beneficial bacteria and the nitrogen cycle would be established in this way. If you ever did changes to the tank, you would have to be careful not to swap out all decorations and the substrate in the same day. Changing out 100% of the water is not an issue, because only a negligible amount of beneficial bacteria is suspended in the water at any given point in time.

That all said, if I ever built a plywood tank, I would built it slightly longer than the viewing glass on one end of the setup. The area not visible through the glass would be separated from the tank by a piece of Poret Filter Foam. All you need is a power head or air lift tube to pump water out of that separate area into the rest of the tank. The water from the tank has to return to that area through the Poret Foam, giving you perfect mechanical and biologial filtration :thumb:

The filtration part can be made as big as you like, and will basically act like a sump at tank level. The beauty with a plywood tank is that you can just built the tank a little longer instead of building or buying a separate sump!










The image was taken from the Swiss Tropicals website, and shows the concept on a 10G glass tank. On a plywood tank the filtration part of the setup would be largely invisible, especially if you used black or brown foam, and planted the foam with Java moss and Java fern for a natural background look.


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## dielikemoviestars (Oct 23, 2007)

Also, when placed next to a 1000g tank, a 100g sump wouldn't be too big. You can find them cheap (less than $1/gal) on a few sites.


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## Rhinox (Sep 10, 2009)

Heating the water would be the biggest problem, other than that, its a great idea. Lots of people use a continuous water change system to keep nitrates low and water chemistry stable, but most can't go without a filter because you need to change a large amount of water to keep ammonia at basically 0. Since you pay a flat rate, you can afford to do it while most can't. I'd want to do a little math first to figure out what rate of fresh water going in will be needed, though, rather than just picking a number out of the air.


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## cantrell00 (Oct 30, 2010)

15-20% per day will more than accomadate nitrate build-up..

You would have to experiment with it but I would be willing to bet that it would buffer any ammonia or nitrite spikes as well.. Well along with the bacteria in the substrate, walls of the tank, etc..

As for temp, you could do direct source heat to the line "in".. Wouldn't have to be heated much. 1000 gallons is A LOT of water & you would have to introduce a huge amount of new water in a short period of time that is also at a much lower temp than the tank to alter it..

I would be more concerned with bound clorine/chloramine than heat or amm/ni/nitrate.

I researched this a lot & seriously considered it for my fish room but using water at that scale was too expensive + chlorine from city water was a deal breaker..

You have the most significant part of the equation figured out. Cost.


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## BillD (May 17, 2005)

fmeullers' idea is a good one, using the Hamburg mattenfilter. They are extremely efficient and relatively inexpensive. Up here a 5' x 10' x 2" thick black sheet is around $185 from the manufacturer (including custom cutting). A friend has a 350 gallon tank that uses only an air powered mattenfilter, and all his 34 tanks use them exclusively, powered by one 45 Watt air pump. They can go a year or more between cleanings.
The only problem I have with the whole idea of continuous water change, because the water is free, is that it is wasteful of water. Regardless of what one pays for water, it is a precious commodity, that should be used wisely, and not wasted. While a goodly amount of my tank water goes down the drain, I attempt to use as much as I can for watering plants and such. Still, I am as guilty as the next aquarist for wasting water.


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## cantrell00 (Oct 30, 2010)

> The only problem I have with the whole idea of continuous water change, because the water is free, is that it is wasteful of water. Regardless of what one pays for water, it is a precious commodity, that should be used wisely, and not wasted. While a goodly amount of my tank water goes down the drain, I attempt to use as much as I can for watering plants and such. Still, I am as guilty as the next aquarist for wasting water.


It will end up at the water treatment plant, filtered, recycled & reused, right?

If you are in an area stricken by drought - I can see the concern. If not, it is no more wasteful than watering your grass..


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## Rhinox (Sep 10, 2009)

So, I did a little math experiment because its the nerdy thing I do when I start thinking about things like this.

The answer (I can give the full details later for those interested) is that I've come up with a relationship between the amount of new water entering the tank, and the concentration of some nasty chemical in the tank in terms of its normal accumulation. The relationship is as follows:

*If you turnover X times of the water per day, and the tank normally accumulates Yppm of Chemical A per day, then the tank will stabilize at a level of Y/X ppm of Chemical A after a time period of about 100/X hours.*

This assumes that the continuous system works analogous to a water change. Like when you do a water change, you're removing nothing but old water, and then the new water you put in mixes with the old so that if you did a second water change right away, you'd be removing some of the water you just put in. The system could be more or less efficient than this depending on the setup, and while it makes sense to me, if I tried to explain it I probably wouldn't do it well and just confuse all of you so just for now accept this assumption please .

So examples to help it make sense...

Example: Suppose the uncycled tank creates 1ppm of ammonia per day, and this system changes 100% of the water per day. The tank will stabilize at a ammonia level of 1ppm/1 = 1ppm ammonia after about 100hrs (100/1.00)

Example 2: Suppose the cycled tank creates 2.5ppm of nitrate per day, and this system changes 50% of the water per day. The tank will stabilize at a nitrate level of 2.5ppm/50% = 2.5/0.5 = 5ppm nitrate after about 200hrs (100/0.5) (50% = 0.5x turnover per day)

Example 3: If the uncycled tank produces 1ppm of ammonia per day, how much water should the automatic system change per day to make sure ammonia stays at or below 0.1ppm? Answer:
1ppm/X = 0.1
X=1/0.1 = 10
X=1000% (10x turnover = 1000%)

Example 4: Suppose you set up your water change system per example 3, but you've underestimated the amount of ammonia the tank produces per day. Instead of 1ppm, its 3ppm - how high will the ammonia climb and how long will it take? Answer: 3ppm/10 = 0.3ppm in approximately 100/10 = 10hrs.

So, conclusions. Basically, its probably not going to be feasible to control ammonia with a continuous system for a completely unfiltered tank for most people. Even if the cost of the water itself isn't prohibative, its probably going to be impossible or improactical to maintain the temp you want in the tank. You'd also need to have an idea of how much ammonia your fish produce, which is not going to stay constant as the fish grow. If your tank produces 5ppm per day, turning over the tank 10x per day with fresh water is still going to reach an equilibrium of .5ppm ammonia in the tank after just 10hrs, and thats higher than I'd be happy with. Turnover of 50x per day to keep ammonia at 0.1. For a 1000g tank, thats 50000 gallons of water per day...

So you're going to need biofiltration for ammonia and nitrite. Its true that bacteria will form on tank decor and substrate, but knowing that I'd definitely need good biofiltration, I'd probably want to have some type of filter. In any case, assuming you have biofiltration, your ammonia and nitrite is going to be 0 all the time, and you can figure out how much water you want to turn over based on how much nitrate you'd be comfortable having at a constant level. If your tank produces 5ppm of nitrate per day, and you'd be happy with a steady state level of 20ppm of nitrate for example, you would only have to turnover 25% of the water per day with fresh to get to that 20ppm steady state level of nitrate - ammonia and nitrite are still 0 due to the biofiltration.

So my recomendation is to have some kind of a filter, and set up your continuous system to control nitrate only and let the filter handle the biofiltration. The more water you turnover, the lower your nitrate will be, but I wouldn't count on the continuous changing to mean you don't need any filtration whatsoever. You're going to need biofiltration.


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## cantrell00 (Oct 30, 2010)

> So, conclusions. Basically, its probably not going to be feasible to control ammonia with a continuous system for a completely unfiltered tank for most people. Even if the cost of the water itself isn't prohibative, its probably going to be impossible or improactical to maintain the temp you want in the tank


Alot will depend on the bio-load (1000 gallons is ALOT of water to dilute the concentration) & how much water movement you can maintain. If the tank is stagnant, I agree - controlling ammonia will be very difficult to do. If using powerheads to keep the water moving back & forth - you could make it work. Something similar to a reverse under gravel filter comes to mind. Sand can make for an ideal bio filter medium assuming you can eliminate dead spots & keep the nasty bacteria flushed out of it.

As for the tank temp, I assume it will be in a heated/cooled room/basement so all we are really talking about is the difference between the ambient temp of the room & the desired temp of the tank. Basically, a 5-10 degree variance. The one variable that can't really be predicted is the water temp that is being added. It would also vary by season. But 25% over the course of 24 hours regardless of the temp being added wouldn't seem to be enough to alter the tank temp to the degree where it would effect the fish. I don't know the equation to prove it mathematically. More my gut than anything.

25% water change per day absolutely would keep nitrate in check though...

A part that is missing here is mechanical filtration & removing particles. If you want the water aestheticly pristine, you will without a doubt need some type of mechanical filtration.

Honestly, fmueller's poret "Berlin" method he recommended is an excellent approach & simple.

Maybe do that + a 25% daily drip/change.

I shudder at thinking of having to change 50% of 1000 gallons once a week without some pretty significant automation. A continuous drip is a easy way to accomplish the same. Perpetually.


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## newguyinillinois (May 1, 2011)

WOW!!! Talk about feed back!! Thanks everyone. Ok this is what I have in mind. My tank will be an in wall affair, only one viewing window. So I am going to wall off the whole end of the room. The room is 13 feet 9 inches wide. i am going to build a wall across the end of the room creating another room 56 and a half by 13 feet 9. The tank will be 48 by 48 by 96 inches. The viewing window will be 36 inches high and 84 inches wide. It will be from 3 feet at bottom and 6 feet at the top. I am going to control temp by heating the entire room. im going to raise the temp of the incoming fresh water by having it flow through 5 125 foot long garden hoses which will be kept in the room. For water circulation, i plan on using a 1000 gph submersible pump in each corner for a total of 8. I will orient them to create a whirlpool effect. Im going to install a grid of half inch pvc in 6 inch squares with quarter inch holes drilled at each intersection pointing up. This will be connected to a 1200 gph sub pump to create a ugj. Im using 3/4 inch gray crushed slate as substrate. I will put a diy foam filter on the intake of each circulation pump to help keep water clear and promote beneficial bacteria. I know that with that many pumps running ill be using enough electricity to run a proper filter, but a filter reqires maintenance. this way my cleaning duties will hopefully be limited to rinsing off two 8 inch cubes of foam a week. By the way this hole idea started when i got a one inch piece of annealed glass out of a mini storage unit for free that is 90 by 42. It has to be a sign. build a big tank to use this on.Then a month later i found the most awesome piece of driftwood on a canoe trip thats about 32X36x70. So im just waiting on my income taxes and its on. Please continue the suggestions.


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## cantrell00 (Oct 30, 2010)

newguyinillinois said:


> WOW!!! Talk about feed back!! Thanks everyone. Ok this is what I have in mind. My tank will be an in wall affair, only one viewing window. So I am going to wall off the whole end of the room. The room is 13 feet 9 inches wide. i am going to build a wall across the end of the room creating another room 56 and a half by 13 feet 9. The tank will be 48 by 48 by 96 inches. The viewing window will be 36 inches high and 84 inches wide. It will be from 3 feet at bottom and 6 feet at the top. I am going to control temp by heating the entire room. im going to raise the temp of the incoming fresh water by having it flow through 5 125 foot long garden hoses which will be kept in the room. For water circulation, i plan on using a 1000 gph submersible pump in each corner for a total of 8. I will orient them to create a whirlpool effect. Im going to install a grid of half inch pvc in 6 inch squares with quarter inch holes drilled at each intersection pointing up. This will be connected to a 1200 gph sub pump to create a ugj. Im using 3/4 inch gray crushed slate as substrate. I will put a diy foam filter on the intake of each circulation pump to help keep water clear and promote beneficial bacteria. I know that with that many pumps running ill be using enough electricity to run a proper filter, but a filter reqires maintenance. this way my cleaning duties will hopefully be limited to rinsing off two 8 inch cubes of foam a week. By the way this hole idea started when i got a one inch piece of annealed glass out of a mini storage unit for free that is 90 by 42. It has to be a sign. build a big tank to use this on.Then a month later i found the most awesome piece of driftwood on a canoe trip thats about 32X36x70. So im just waiting on my income taxes and its on. Please continue the suggestions.


I like the UGJ idea with prefilters on the return side of the pumps... I would recommend PFS instead of the slate though...

I am iffy on the hoses to heat the water but if they returned the water at a rate that equals a 25% water change over 24 hours, there may be enough retention time in the hose to where it would be heated enough before it drips into the tank. Honestly though, I don't think you will need it. 1000 gallons X .25 = 250 gallons per / 24 hours = 10.41 GPH... I just do not believe that is going to effect the temp of the tank as whole... No way...

Great grab on the free glass.. I highly recommend you search VLDesign @ monsterfishkeepers.com. He built a successful 1500 gallon ply/glass tank & has plans for it on the site. Would be a good reference for the structural aspects of the design..

Best of luck!


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## Chunkanese (Feb 4, 2011)

watch out for chlorine spikes....


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## Vadimshevchuk (May 23, 2009)

idk why you would want like a 180 gallon sump with a pump that reefers use that can push 5000 gph and call it a day with a couple of powerheads? I think it sounds easier then to keep heating all that water coming in.


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## newguyinillinois (May 1, 2011)

huh?


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## Vadimshevchuk (May 23, 2009)

Sorry i met wouldn't. I would just look on craigslist for 180 gallon tank to make that into a sump. I think that would be easy to clean since sumps are easy to access and just use a pump like this http://www.bulkreefsupply.com/store/ree ... 5-gph.html for a return then i assume all you would need like 4 power heads and you and that should work be good for filtration.


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## vann59 (Jun 20, 2011)

All this just to avoid getting a few large canister filters? I know I'm just being sour grapes here on some serious engineering, but... :lol:

If you have chlorine or any toxins coming in the water, you would have more work dealing with it, and if the water lines had to be reworked and water was off for any period, it would get ugly pretty fast wouldn't it?


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## newguyinillinois (May 1, 2011)

I dont have room for an 180 gallon tank. my ceiling is 96 inches. the tank will be 48 inches plus 5 1/2 inches for the bottom supports plus 3/4 inches for the plywood bottom. plus 3/4 inches for the plywood top. That is 55 inches total. So that leaves 41 inches minus 24 for a 180 gallon sump. that only leaves 17 inches. Thats not enough room for maintenance.

What is more likely, a power outage no canister filters, or no water??


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## vann59 (Jun 20, 2011)

newguyinillinois said:


> I dont have room for an 180 gallon tank. my ceiling is 96 inches. the tank will be 48 inches plus 5 1/2 inches for the bottom supports plus 3/4 inches for the plywood bottom. plus 3/4 inches for the plywood top. That is 55 inches total. So that leaves 41 inches minus 24 for a 180 gallon sump. that only leaves 17 inches. Thats not enough room for maintenance.
> 
> What is more likely, a power outage no canister filters, or no water??


It's true that power outages happen more often, but a generator could get you through a pretty long power outage. I would personally not be comfortable going away and leaving water running though, in the event something went wrong, it would be a mess. I suppose if you have a really secure drainage, such as a floor drain, it would be a lesser risk.

I think if your house was on pilings over the water, and your drainage went into the water below, that would be an ideal scenario.

If you can make it work, it would be interesting to hear about. Good luck with it.


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## kodyboy (Dec 9, 2007)

you could make a huge "box filter" out of one or two small garbage cans and a large powerhead or two.


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## newguyinillinois (May 1, 2011)

"box filter" ??? Please elaborate.....


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## fmueller (Jan 11, 2004)

http://www.csupomona.edu/~jskoga/Aquari ... ilter.html


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## newguyinillinois (May 1, 2011)

No. that wont work. I dont want any visible and unsightly containers in my tank. I have been taking into consideration, all of the ideas that have been sent to me on this thread, and if I do end up needing some form of filter I think im gona ad some large bulkheads on one side and plumb a couple intakes for two 3000 gph pumps. then just put a 4X48X48 inch piece of black filter foam a couple inches in front of the pump intakes as shown in the pic on this thread, only its a pic of a ten gallon. hang some bags of carbon and b done with it. but hopefully the water will stay clear enough without it.


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