Oase canister filter leaks when power is off. 

use silicone grease all over rubber gaskets at least once a year. i had 350, now 650. no problems at all, but first thing I did was grease.

I'm the same way shut down all pumps and was looking to buy this right now to upgrade my current set up, maybe the gasket seals are bad?

Did you find out what was wrong? Mines doing the same thing

worse filters I have . and oase have terrible customer service.