Bio-Wheel stopping and starting

It's a good sign, really. Your Bio-Wheel is getting saturated with water and bacteria and naturally this will make it heavier and slower in terms of rotation. In fact, it's ok if it turns maybe once a day as the bacteria are still thriving in that area of your filter system.

try lifting the cartridge behind the slow wheel. If it's clogged, lifting it will increase the waterflow to the wheel while still allowing the cartridge to catch a lot of debris. You could also clean the cartridge or replace it. Personally, I just rinse mine off well in tank water and put them back in. I haven't bought a new cartridge in a year.

Waterflow is probably what's slowing your wheel. If not, the bearings could be dirty. Barring that, the wheel may just be very well cultured and acting as it should. Good luck!

Both the wheels in my Penguin Bio-Wheel Mini's have slowed down a bit...but the water is still nice and clean with no nitrites or nitrates. The bearings are probably a little goob'd up, but as long as they turn once per minute, they're turning more than they have to. They only have to turn fast enough to keep the wheel wet.

v/r, N-A