From 1 gallon to two and a half!!! YEAH BABY *in my best Austin Powers voice*so before you ask here are the pics!! It has an Aquaclear 30 for a hang on fuge and an Aquaclear 10 powerhead (but you cant really see it) for movement. I think this one looks even better than the 1 gal. I used the rocks on the plate pictured plus the ones from my 1 gallon. So what do you guys think??