ok I went to a lfs that i've never been to recently and saw something unusual. On the counter was a 1/2 gallon cube with a light hanging over it and the smallest filter i've ever seen. In the tank was a tiny clownfish, not sure what kind. I asked the woman working there if this is healthy for the fish and she said as long as you do a water change every 12-14 days its fine. It just sounds a little off to me. According to peoples responses, I am thinking about putting something in my 2.5g. Is it as easy as this person says and can a clown, goby, or shrimp live happily in a 2.5? thanks.