So, yesterday I was cleaning the filter ( puting it in a cup pf tank water, and sort of wiggling it around.) And I noticed that in seconds the water went from clear,to so murky I couldn't see the bottom. The problem was, it was the color of the good bacteria, so was I getting the good bacteria off? I was also rubbing the food flakes, from the filter cartridge, and the brown stuff still came up. It took me almost 5 cups of water to hardly do any damage at all. Help!? Another thing is, that when the brown stuff came, it had a oil-like look as it left the filter cartridge??? again, HELP!?