My biggest bronze cories are almost 3 in long and swim around a lot, so I don't think they're a good choice for this small a tank. If you want a cory species, it would be better to choose one that stays below 2 inches and is less active.sylvia said:4 bronze cories would also be ok
Well, I disagree. It's not about how much waste they produce or how hardy they are, it's about how much space they should have for their active swimming. For an active 3-inch cory I think it should be 20-25 gal at least. There are plenty of cory species that grow only to about 2 in, so why not go for them instead when a small tank in concerned.sylvia said:Actualy I think 15 gallons is resonable for cories but they are active. Bronze are by far the hardiest and most cories grow to 3 inches but are counted as half their size because they don't produce a lot of waste.