I move stuff around all of the time. I have a lot of madagascars as well. I use my indoor pond for them during the winter and my tanks for my CA in the winter. When it warms up I move my Madagascars to my tanks and put most of the CA's in the pond. When in tanks I keep only a pair for the CA per tank. Most of them I use dividers to keep the males from killing the females or vice versa.