Oh OK. I love doing then water changes. My wife thinks I'm nuts but I find it relaxing to do. And in my 45 I have 9 neon tetras, 4 Harlequin rasboras, 7 guppies, 6 cherry barbs, 5 glo light tetras, 3 peppered Corie's, 2 dwarf gouramis, and an African frog. With a fluval C3 and a C4 for filters...