Hi all I've had my 55gal. tank up & runing with about 50 lbs. for 4mos. I have a hangonthe back fillter and a protine skimmer. I just added a wet/dry about 3 weeks ago the guy @ the fish store said to start taking out the bio ball in about 2 more weeks, about 2 hand fulls a week and start to replace them with little pices of live rock is this right? he said if I leave the bio ball my nitrate will go thru the roof?