I started a 2.5 gal planted tank about four months ago. It uses 18w Coralife compacts, fluorite substrate and a DIY yeast CO2 system (scaled down to fit in a .5 L bottle). Needless to say, my plants are exploding, and my two amano shrimp and oto keep it fairly clean. I change water fairly often, but it only really needs it after two weeks. Consitering the bio-load on the system (a betta and two danios, plus the cleanup crew), I am really suprised to see how stable it is.