I have maxed out my current 210 gallon tank with number of fish. I also have a 40 and 65 that are set up as specie specific. Beyond that I have a 10 gallon that is for juvies or a quarantine tank as need dictates. Lastly, a 20 high that I have been moving females from the 210 into as I am working towards the 210 being a mixed male Malawi tank. After a period of time I will rehome the females, but I want to wait a bit of time to verify that they are not males. I think I need to have a bigger tank for the females and hybrids that happen in the 210. It wouldn't be out in a living space. It will be in an unfinished side of the basement with the other tanks. I have read on this site that a 48" tank, either a 55 or 75 is really not the greatest tank for Malawi fish, but I really don't want to spend the money for a six ft tank. What thoughts can you offer?