I removed the closure to check the sand level and now can't get it back on without leaks. I replaced the gasket (new) with a coating of pool lube but still leaks. It is losing all pressure when the pump is off which is causing me to lose prime, and my pump is higher than the pool so it takes forever for it to re-prime (worried about what that is doing to the pump). Finally bought some Flex Shot and put a thick bead around the entire circumference just to stop it for now. Is there a thread sealant that would work for this (fiberglass) or any other ideas?