I have 20 mbunas and 2 bristle noses in a 55 with an FX5 and 2 sponges running. I have no aggression troubles, as there is always someone bigger to swoop in and stop anything out of the ordinary. Do you think I'm overstocked, for a 55? How many fish total are in your 175? I know mine will grow and will move them up to my 125 someday, but do you think my numbers are okay now? I do a 40-50% water change once a week. Your tank is totally beautiful by the way!