I'v had my AGP for 22 yrs. Had been using chlorine for all those yrs,recently had a new liner installed and was talked in to trying Bacquacil. OK so far but thinking of going back to chlorine next season. During those 22 yrs I have purchased 3 automatic chlorinators. The problems is can't get the covers off to replace puck without disconnecting the whole apparatus and putting the darn thing in a vise. This happened to all 3. My question is anyone know of a brand that works?