Canister filter with overflow?

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Aquarium Advice Newbie
Feb 8, 2007
I'm thinking about starting a saltwater aquarium and have thought over a couple of designs. I'm very new to the hobby , so I'm not sure if what I want to do will work or if its even necessary. This would be a fish only aquarium.

What I was thinking about doing is cutting a PVC pipe in half and placing it in side my 29 gallon tank (sealed with silicone). The top of the pipe would have groves cut out to act as an overflow. The water would spill into the pipe and through bio balls to help with biological filtration (sort of like a wet/dry filter I suppose). Next the water would trickle down below the balls into a small reservoir where my canister filter(a Rena Filterstar xP1) would pull it up and out of the tank, do its thing, and return the water to the tank.

See my attached picture for clarification.

Would this work?


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(Moved to hardware Forum)

Welcome to AA :D

Yes and NO.

Yes the way you describe it would work.

No because evaporation would be too great within a day and the canister would run dry.

That's only if you want to "skim" the surface. Otherwise it's pointless IMO to do it.

Either way you don't want bio-balls in a place that's hard to get to i.e. PVC attached with silicone.
What if I drilled a small hole towards the bottom of the PVC pipe to allow just enough water to flow into it, thus preventing it from running dry.

As far as the bio-balls, I probably could make some sort of basket to put them in.

However, you are saying the results wouldn't be worth the effort?
If you stock your tank with 1.5+ lbs per gal of base/live rock it will provide all the bio-filtration you need without the use of the canister.

If looking for cheap live rock checkout or
which has lr for as little as $2-$3 per lb shipped.

Couple of more places with quality lr:

One hole wouldn't provide enough flow for most canisters. You would need many holes and IMO even with a basket not having easy access for waste removal is not worth the effort.
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