Well I decieded to take my magnum out from under my house to be used on my tank. I hate cleaning the micron cartriges every week and I dont like putting carbon in the carbon media containers. I was thinking of putting ceramic rings but the last time I did this my magnum started making alot of noise and didnt pump out much water. I think it might have been the dust from the rings that caused this? Well after using the "search" button Ive read somewere that you can take the center piece of the micron catridge and fill the entire outside of the center piece with ceramic rings. Ive tried this and my certer piece from the micron cartridge dosent fit its too short. Did anyone try this with there magnums? was your center piece short or did it fit?