So I've got a magnum 250 and a C-220 and found an old Bio-Pro 60 assembly at the OLFS... I'm going to do a 30B (at least that's what I told my wife) that needs fairly high bio function and ease of maintenance.
Gonna put the chain: Magnum 250 > C-220 > bio-pro 60.
So I fiddled with the 'kit' that comes with the magnum and the bio-60 and rigged the hose connect to the c-220 then started it up.
Hoses were right, everything was happy. The 220 started going hrumptt hrumptt hrumptt.
Turns out probably ten thousand people have thrown fits, cursed Marineland to hell AND endangered their fish and pocketbooks over one simple problem.
The impeller inside the C series canisters, definitely the one in the 220, is made of end-cap, shaft, magnet, blades, retainer hub and lock-ring.
My impeller's retainer hub had fallen away from the magnet assembly and the open tolerances inside the motor housing allowed the magnet to climb and spin freely, bounding off the impeller blade ring.
Its SUPPOSED to do that! Safety feature so the enclosed and sealed winding assembly won't overheat.
I can only wonder how many tens of thousands of units were sent back because someone left out a tedious little bit from the manual. It can pop off from shock, back-pressure from water or I assume being physically jammed by a piece of ring. (lets hope it works when it IS supposed to!)