Can anyone think of why my Aquaclear 200 keeps slowing to a trickle? I just replaced it because it was outright stopping. Now, the new one (which hasn't accumulated gunk) doesn't seem to really be doing what it should either. The water used to come pouring out smoothly, and now it's reduced to a small trickle. I'm changing the poor things every few days to keep up with the difference!

Could the filter be at a weird angle...or not getting all its power? I have mesh around the end of the tube, so it shouldn't be picking up clumps. How far down should the tube extend? That is, should I use the tube extension for an 18" high tank?

Thanks in advance.

Emily