Currently i have in my 4 ft tank, 2 firemouths, one at 1" and one at 3", 3 convicts, a normal and a pink, both at 2" that have paired up, and a lone 1", 3 severums 1 5" green, 1 4" Gold and a 1" gold, and also several other tropicals. These fish have been together for several months and are doing great. The pair of convicts have taken over about 12" square of the tank and have spawned, but this isnt a problem. The only other thing of note is the larger firemouth that keeps displaying to the severums, but doesnt actually get aggressive. This lasts for about 5 minutes each day, and then he gives up. Good luck with whatever you decide.