i put all sorts of fish together. Mollies and plecos and neons and one black moor goldfish and some pretty fish that i cant name but got from the community section at petco and 1 betta (he has his own tank now) and a red tailed shark and 2 koi (until they got to big) and a CAE and probably more soon. All in like a 50-60 gallon tank. For now plans to upgrade in about 6-7 months maybe by next september.