I have 11 of them in a 20 tall along with 7 LDA-08's, been sharing the tank for a couple months now. Filtration is an aquaclear 200 side-by-side with an aquaclear mini, and a diy sponge filter on an air pump. (Actually my QT tank, but lacking a suitable larger tank to move them into their stay was extended.) They'll be moved into the 33 long after I get the 220 situated and move some fish around. Very mellow fish overall, occasionally chase one another around a bit but it's all bluff.