If the fish are small and you have very good filtration you should be good for now.
Once they get big, probably 2 green terrors or parrots is the max that you'd want to have in it.
Full grown I would only have the 2 green terrors in their and I think that's pushing it, and maybe pleco of some type.. Your gonna need a monster tank for the RTC, unless you plan on selling it or giving it to a local aquarium.. What type of filtration do you have running?