Wow, that's a lot of big fish for that size tank. I know you're supposed to overcrowd African cichlid tanks to disperse aggression by not allowing them to become territorial, but that still looks like a very heavy bioload. I really like the red one.
I'm running an XP3 (350 gph), Fluval 404 (340 gph), and an AC 70 (~275 gph), for a total of 965 gph of filtration. I also run a powerhead attached to a large sponge filter which is hidden behind the rock/facade on the left. I test regularly, and do a 30-40% water change every 5-7 days, with smaller "gravel vac" changes every 2-3 days. So far so good!
The bowl rock is quite porous, I do have a pleco in there but the cichlids seem to do a good job keeping the pockets empty. They're constantly spreading sand to the tops of the rocks, removing said sand, looking for food...
All that said, a bigger tank is very likely in the near future