got a 75 gallon up and running and was wondering which one to go with. I will get three of them; keep the 2 male and female ones (since i was told they are impossible to sex when they're young i will get 3 to up the chances of getting a pair). i have no experience with either so was wondering if anyone did and which one has more personality? also, how long will it take a 3" one to grow up to about 9"?