I agree, definitely a larger tank. I've kept them in 20L and 29g's. They aren't very active fish, but do like a well planted tank and spend a lot of time propped up behind or under something. Some of the darters I've collected by shuffling through rocks in fast moving creeks, these swamp darters not so much, but they still seem to like a well structured scenario. They are very goby-like in behavior.