# Who runs filterless aquariums



## EntoCraig (Jun 7, 2010)

james0816 said:


> Curious about this. I think this will be the next rhelm I venture into to see what I get. I've always had some type of filtration on my tanks.


Well my QT tanks are filterless :lol:

I know the salt ware world often uses no actually filters and just water flow within the tank to filter naturally. I assume this could be done with a planted tank with the proper flow within the tank, as well as enough places for bacteria colonie to grow (porous gravel, porous scaping rocks, etc)


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## BruceF (Aug 5, 2011)

I run some. I keep only a minimum of fish in them, sometimes none at all. I find they still benefit from large and frequent water changes, especially if they have no water movement. Without co2 I find that dirted tanks are the easiest way to keep the plants growing. 
It is pretty cheap to set up a ten gallon tank this way with a clip light and a cfl bulb. 
I find that if I add a power head I almost inevitably add a sponge filter of some kind.


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## Wy Renegade (Nov 29, 2011)

I talked to a bacteriologist this past summer about bacteria in freshwater vs. saltwater. We discussed the fact that in the saltwater world they often relie on bacteria to do the filter utilizing both aerobic and anaerobic bacteria. He pointed out that ponds and lakes in the "real world" utilize the exact same system and that there is no reason that it shouldn't work for freshwater just like it does for saltwater. I haven't personally ventured there yet, but it is an area I'm planning to dabble in in the future.


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## bikinibottom (Nov 18, 2012)

Guess it depends on how you define "filter". In the saltwater hobby, I've kept "filterless" tanks. I had HOB refugiums that had a sponge in one of the chambers to catch big stuff, and the refugiums were full of macro algaes to take up nitrates. I had powerheads for water movement, but other than that I depended on a "biological filter" to process waste -- bacteria, snails, crabs, worms, etc. Worked pretty good, too... I would go several months without needing to do water changes, and the corals would grow like crazy to the point I had to start giving it away. But with this method I couldn't keep a large fish load (the most I ever kept was 5-6 very small fish in a 40 gallon tank).


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## lochaber (Jan 23, 2012)

Wy Renegade said:


> I talked to a bacteriologist this past summer about bacteria in freshwater vs. saltwater. We discussed the fact that in the saltwater world they often relie on bacteria to do the filter utilizing both aerobic and anaerobic bacteria. He pointed out that ponds and lakes in the "real world" utilize the exact same system and that there is no reason that it shouldn't work for freshwater just like it does for saltwater. I haven't personally ventured there yet, but it is an area I'm planning to dabble in in the future.


Actually, I believe this is mentioned in Walstad's book (which I highly recommend). She discusses biofilms, and how there can be communities of both aerobic and anaerobic bacteria in the same biofilm. Also, the soil contributes to this, with the deeper areas having limited oxygen, and fostering anaerobes that will remove nitrates.

I can't remember if it was that book, or somewhere on the forums, but I've also heard speculation that the same process can happen within the pores of driftwood.


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## Knotyoureality (Aug 3, 2012)

Most of my smaller tanks (3g and under) are filterless. Very low bioload--snails, shrimp, endlers at the most--moderately planted, weekly wc range from 10-50% depending on type of vessel, how heavily planted it is and bioload.


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## DerekFF (May 24, 2011)

Ive only done it on 5g and less

Sent from my DROIDX using Tapatalk 2


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## STS_1OO (Nov 28, 2012)

The only way to get these sorts of tanks to be successful is to have a high flora-mass and a low fauna-mass (effectively a Walstad tank). 

If you're more into natural, haphazard growth and plants rather than a lot of fish, this is a fun experiment.


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## Rev_jim_jones (Sep 25, 2011)

I seem to remember people running several Canisters in a row the last few with no Pumps to get anaerobic Bacteria to Populate them. But that was several Years ago and haven;t really heard a peep about it in awhile.


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## vqfive (Nov 5, 2012)

In my Reef tank I had no filtration. My sump was empty just used it for more water volume. I tried this on my 20g that is heavily planted. Took out all the filter material from the canister. In a few days my water looked cloudy so I put it all back in.


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## BBradbury (Nov 8, 2010)

*Filterless Tanks*



james0816 said:


> Curious about this. I think this will be the next rhelm I venture into to see what I get. I've always had some type of filtration on my tanks.


Hello james...

I run a tank with no mechanical filtration. It's filtered by emersed land plants. Attached is pic if you're interested. The plant roots take in the toxins produced by the roughly 75 Fancy Guppies in the tank and return pure water to the tank. I just replace a little water that's lost to evaporation. I do have to trim the plants sometimes too. Maintenance takes 20-30 minutes a week at most.

B


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## ramen lover (Jun 22, 2012)

BBradbury said:


> Hello james...
> 
> I run a tank with no mechanical filtration. It's filtered by emersed land plants. Attached is pic if you're interested. The plant roots take in the toxins produced by the roughly 75 Fancy Guppies in the tank and return pure water to the tank. I just replace a little water that's lost to evaporation. I do have to trim the plants sometimes too. Maintenance takes 20-30 minutes a week at most.
> 
> B


that's pretty cool looking. When you have to get inside to the tank to clean it, is it a pain to remove all those emersed plants from the top without making a mess?


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## BBradbury (Nov 8, 2010)

*FW Tanks w/o Filtration*



james0816 said:


> Curious about this. I think this will be the next rhelm I venture into to see what I get. I've always had some type of filtration on my tanks.


Hello James...

I run freshwater tanks without using mechanical filtrtion. I'm currently running a 45 gallon tall tank. I filter the water through the roots of several Chinese Evergreen plants. The roots take in the dissolved nitrogen from the fish waste and return pure to the the tank.

B


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## kwheeler91 (May 26, 2009)

Plants are your best friend when trying to acheive anything close to filterless. Fast growing plants like stems and especially floating plants like frogbit and and duckweed suck nitrates out of the water at extremely fast rates do their growth speeds. since they arent limitied by co2 and are closest to the light they are water cleaning powerhouses.

Most of the bio filter will form on your wood and rocks and plants, especially if you dont run any media in your filters maybe a coarse sponge for mechanical, but you will definitely need good flow and oxygen levels if you want to keep a good amount of fish.

Think about nature, rivers and streams dont have media baskets and sponge filters, just surface area and flowing water full of oxygen. Ponds dont have flow, but they generally have lots of vegetation, or algae that also eats nitrogenous waste. Both will have a proportionate amount of bioload. 

Basically just use common sense, keep things balanced, and choose species according to the conditions you are going to emulate.


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