agree with ARAKKIS, i've kept up to 50 tiny fish in that 20 g be4 and they were all healthy, the water condition is perfect(water change 75% evry weekend). it just needs more care and time into it to house the 20 cardinals and 15 brigattaes together. Somehow i find galaxy rasboras rlly interesting to watch, however i dont fancy their coloration much, it looks too dull if u if u look at them as a whole not individually. but cardinal tets looks fancy whether seen in a shoal or individually.