You are correct. I checked all my plugs and blew out the line in case of debris. Then I noticed a small leak around the large round seal at the top of the filter. I didn't see at first because when I backwash it drains around the side of the filter. I have never gone into the filter. Do I just take the top off and replace the seal? Do I have to buy the seal at a pool store? Do I have to drain the filter first? Sorry for all the questions!! I don't know anything about this but can follow directions well!!

Janis