Right now,I am currently cycling my 125 gallon tank,for my South American Cichlids.My current tank set up in my 55 gallon,my ph level is 7.4.Should I have my PH level at least between 7.0 or 7.4,so that it wont kill my cichlids in my new 125 gallon set up?I have heard stories,where people lowered their ph from 7.6 or whatever to 6.6 and it killed the fishes.