I agree, you should put more than 10 in there. I have a 210g and I had 16 4-5" discus in there with 3 motoro stingrays and an arowana. I have 3 xp3's on it. I say had because I switched the discus to a colony of fronts because my aro. was going faster than the discus and he started to pick off the slow growers.
