okay i bought a tank setup used, cleaned it all. then i noticed the bio wheel was missing from the filter housing. so i went and checked LPS and they don't carry it at all only special order. my filter i have is a penguin 200 by marineland, so it has to filter slots. what i thought about doing was putting the filter in the back slot and using bio balls from marine land would work/do the same thing as the bio wheel, if i filled the front half of the filter tank up.