I have had them, as a single fish (years ago), and as a threesome of juvies for a few days recently, until the only slightly larger one harassed another to death. Now I have two in separate tanks. At the LFS they have a tank with a bunch of them (all juvies), and they seem OK, but they have not had them long. It is possible that 6 will work for you but I would provide lots of driftwood and obstacles so they can avoid each other. As a threesome, it did not work for me.