So I have a 55 gallon freshwater set up right now that has been running for about six months. All the chemistry is finally perfect now and the fish seem to be perfectly happy. I have 2 leopard ctenopoma an african brown knife a sengal bichir 2 german blue rams 2 rubber lip plecos a banjo catfish and an african butterfly fish. MY question is will the space I have be enough room for about another six months and when I upgrade will a 75 gallon be enough or will i have to get a 90 gallon.