Well, your first thing off is to get a pair of Oscars....and for that you should have a 125 gallon tank. A 75 may work. If you want to start from scratch, get 6 youngins, and you will get atleast two that pair off. Make sure the pet shop will take the other 4 back when the time coms, because 6 oscars need a good size tank. I keep 4 in my 180. Big fishies when they are all grown up.