ksabby

Hi, I have a 35 gal tank with a 170 gph biowheel filter and when I do a water change ( 15% +/- ) the water turns very cloudy and green whithin a few days but then clears up after a week or so later. I have a total of 11 fish in the tank and some live plants. I do not rinse the bio wheel when I do a water change. Can some one tell me what I am doing wrong? Kurt..