do mbunas like alot of flow. cuz i was thinking of having powerheads with about 400gph on each end of the tank to keep things circulating. or is that too much. its a 55g.
I have one in my 55gal when i had the Mbuna and they were fine and now the 55gal is a Tang tank again still the same powerhead and still no issues i think you would be fine..
I've got 2 fluvals on mine (one with regular nozzle, one with a spraybar) and the ugj with a good output, none of mine seem to mind it at all, in fact they always swim in the current.
I agree with Pit and efors, they should be fine, if anything it doesn't hurt to try, plus your tank would be cleaner.
If that's the case, to have 2 powerheads won't hurt as ibr3ak said; but IMO, it is not necessary. Two filters and 1 of those powerheads is enough, I think.
I think your fine if you do weekly water changes and also put those cylinder shaped sponge inserts on the end of your powerheads.. You don't want to create a jacuzzi aye..