Penguin Biowheels Noise and wheels turning only sporadically

Anyone have any insights on why my penguing biowheels will sometimes (and always the same ones) make a grinding sound, stop for a few minutes and start all over again. Since I live in a studio apartment, the aquariums are in the same room so the only alternative I have is to turn it off. I bought a larger aquarium and got a Penguin 400 and from the very start, it made the grinding noise so I luckily was able to return it. It gets expensive buying these things and half the time, either the biowheel isn't turning or it's making noise. However, I have so many cartridges, changing brands doesn't make sense on top of the chemicals the biowheels remove....when they work. HELP!

Do you have a sandy substrate?

Mine will make grinding noises and occasionally stop if sand gets into the impeller well. Sometimes it'll get kicked out of there on its own and restart and other times I have to take it apart and clean it well. A prefilter on the intake will usually eliminate the problem.

wipe off the spindles on the bio wheels. Clean out the holes in the spray bar with a tooth pick. Clean the impeller in the sink.


Do you have snails in your tanks? That really sounds like a snail committing suicide in the impeller.