I'm considering a 72G bow front with Blue Acara and Green Severum. I'm not that familiar with the American cichlids, what would make a good mix of these fish in this size tank?
You should have no problems with them. Both species are quite hardy and mid tempered. Peaceful for the most part.
Chances are that in 99% of the time (except when feeding.) they will completely ignore each other.
The acara is a mid to low range swimmer and the severum is a mid to high range swimmer.
OK, thanks. And what would be comfortable stocking levels for these in a 72G tank? I'm not especially concerned with breeding so do I need to be concerned with a particular M/F ratio?
I had 4 in my 77 gallon with no problem until they paired up.
The 2 bigger ones beat up the 2 smaller ones, so I had to remove the 2 smaller ones into another tank... Then they paired off.. but anyway.
You should be ok with 3 in the 72.
As for the acaras. It depends on the fish. I have had very docile ones that I had 4 or 5 in the 77 gallon. Then I have also had a couple of nasty ones that I could only keep 2 together. For the most part though. Assuming you set up some caves and have enough hiding spaces. 4 acaras in the 72 should work fine. That would be the max though. Under that would be less risky.