I read that the cyaneus get up to 5 inches whereas the viridis get up to 3.5 inches...is this correct? How long does it take for them to reach adult size typically? 5 inches is pretty big for having a school of those and if that's the case I may just have second thoughts about getting a few of them them. (I was planning on getting a school of 5 for my 72 gallon)