I have a 125, and I thought it would be a good idea to add a school of tiger barbs as dithers fish. I added about 40 small tiger's thinking my cichlids would thin the herd abit. But that it would take time. I have an RTM and 2 Jack Dempsey and two Festae. All about 2 to 3 inches still growing. Well, they made quick work of those tiger barbs and now I'm down to 10 in two days. Yeesh. Lesson learned.