I have a 90 gallon tank. Will be adding 30ish mbuna when I order (1-2 months) Want to get my 2nd filter (new today) full of bacteria. I have two Emperor 400's. They are each rated up to 400 gallons per hour, so a total of 800 gallons per hour on a 90 gallon. Will this be enough with once weekly 50% water changes?