The issues I've had with the marinelands is primarily the valve block. It comes with O rings to replace but there are some internal faults which usually cause leaks after reassembling when cleaning, and letting air into the system causing a very noisey, sputtering canister. The customer service however is one of the best companies I've ever delt with. The main reason why I kept them so long, they would send a whole new filter in exchange for the motor head.
Sent from my iPhone using
MonsterAquariaNetwork app