i don't knoiw what kind of fish you want to mix, i was told that it was ok to keep an african in a ca/sa community tank as long as you only have 1 african. Myself i've been able to keep a polystigma/livistonii and a hemichromis in a tank w/2 O's, a RD,jacks, jags, FM's, cons, and a uro. this tank has been running for 2 years with this mix of fish. Not saying its recommended or ideal, but it can be done.