I'm trying to open the pool for the year..I just bought a salt free system but the connection from the salt water system to the filter is leaking. The connection is a threaded connection inside on the filter and outside threaded going to the salt water system. I have tried taping it several times and have made sure the fitting were tight. It is still leaking just a little and I have tried five times reseating and re-taping the connectors. Any other ideas? Thank you in advance