This is a common cactus and I have trouble growing it. I really love this cactus it is so bright and cheery. What do you pot it in? I tend to overwater this compared to my other cactus, and I am not sure why. Does it do better in a smaller pot? Any growing hints will be appreciated. I probably have 70 cactus in pots and I have trouble with Rebutua marsoneri and Mammallaria zeilmaniana. I kill them regularly. The rest i do pretty well with.