I tried to attach a couple pictures but I've yet to do it right we'll see. I made a filter with a small tupperware container and put holes along outside bottom to let water in but not suck up floating food. Inside I used coarse scruby pads like for pots inside cut to fit around a small fountain pump that attaches to a tube tied to their light. It provides a gentle flow they like to chase their food and even warms the water a couple degrees above room temp. The filter media becomes biologically active after a couple weeks and rarely needs gentle cleaning to rince some of the detritis- poop? I use a siphone tube once in a while to do water changes and suck out stuff. I made a similar larger one for other setups with a small power head. Its the only way I've found to filter such a shallow setup. Its a catlitter pan with non floating,non long string separating, indoor outdoor carpet on the bottom so they can get some grip when they flip over
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