I realized that water will be forced through all the substrate inside the canister when it's new meaning that there won't be any anoxic zone inside the substrate and in time, the substrate will get clog and we are back to the same old problem.

Hi Dr. Novak,

Thanks for the tip on salt!

Regarding using the system or mimicking it with canister, I've been searching for a suitable canister on the market and couldn't find one. As far as I can understand about the anoxic filtration system, it relies on water flowing around the baskets where the kitty litter and laterite will "suck" the "bad stuff" into the baskets. However, the principle on all canister filter is that water is forced through the bio media which is completely the opposite of the anoxic filtration system. At first, I thought if I can stuff enough kitty litter and laterite inside the canister, wouldn't it be the same? But after some thinking, I realized that water will be forced through all the substrate inside the canister when it's new meaning that there won't be any anoxic zone inside the substrate and in time, the substrate will get clog and we are back to the same old problem.

So I started thinking if I was to custom make a "canister", using acrylic to make a 1'x1'x1' box with a 9"x9"x9" smaller box attached in the middle of the big box, meaning that it'd be something like a small box "floating" inside a bigger box where the small box will have maybe 4mm holes drilled on all 6 surfaces. Water will flow in from the top and exit from the bottom where an external pump will be connected to pump the water back into the tank. If need, I can probably ask the acrylic guy to make it so each box can stack up or connect with pvc pipes. That way, the whole thing can be scalable with, say, if you have a small 1.5' tank, a single box should be good enough and if you have a 4' tank, you probably want to stack/connect 4 boxes together. Anyway, the idea is that water will flow into the each box where the kitty litter/laterite would be sitting in the middle of each box and water will flow around the small box inside where it'll have holes for the substrate to "suck" the "bad stuff" inside but the substrate itself won't be disturbed by the water flowing around it.

What do you think? Would it be, theoretically, able to mimic the anoxic filtration system?

Thanks for your time and looking forward to hear from you soon!

Alex Chai.......

It might just work but you would need a pre-filter like I have it illustrated.  The Anoxic filter would have to have clean water going into it or particulate matter would eventually clog it.