pH no problem. High GH? More of an issue. It almost always is. I wouldn't do it; the point of a Mbuna tank is that it is a biotope of Lake Malawi - where tiger barbs etc. are conspicuous by their absence. If you want to mix cichlids with other community fish then the New World species or African riverine species are a better bet, and live in compatible water conditions - congo tetras with Jewel cichlids or Kribs (not together, I don't think
) might work. The very high TDS of a good Mbuna tank is not conducive to long term health in fish from softer, less mineralised waters - i.e. nearly everything else at the LFS. Except the Poeciliid livebearers of course, but best of luck keeping guppies with your auratus.
For ther record, Mbuna are tropical fish, given that Lake Malawi is in the tropics, and they are definitely fish.
For ther record, Mbuna are tropical fish, given that Lake Malawi is in the tropics, and they are definitely fish.