I am up in the air about mixed tanks (AC and SA). I have and had kept both in the same water parms. I don't buffer my AC tank (not into breeding, yet) and I don't soften my Salvani tank. I am more inclined to keep both in my slightly raised pH, hard, CLEAN water. I think the fish like well filtered, areated, clean stable water conditions more than anything. I could be totally wrong, but my fish tell me otherwise.