I have a Penquin Filter 150 and today I did a water change and changed the filter out and when I put a new filter in it the spinny thing (I think they call it a Bio-Wheel) stopped spinning around. I think it is suppose to spin all the time but I can't really remember if it is or not. It is free to spin because it spins quite easily when I spin it with my fingers. And water is going through the filtering system as I can see it coming out of the filter. Is the spinny thing suppose to spin all the time? Any suggestions? I don't want bad things building up in the tank.