I have 2 albino oscar r bout 4 inch of size 2 baby severum 1 small pleco in my 20 gallon. Bt as I read bout oscars I feel d need of a big home for dem. So recently I ordered a tank sized 42"x18"x24" almost a 78 gallon tank.is dat ok for dem? I want to add a firemouth & a blood parrot in d big home wen done. Suggestions r welcome and appeciated.