I have a 6500 gal. fiberglass that has started losing about an inch of water every night. Only about 1/8" loss during the day. It's not evaporation. I did a bucket test last night. The pool dropped an inch. The bucket nothing noticeable. I've checked all of the supply jets and around the skimmer with dye. No noticeable migration. No bottom drain. Can't find any wet areas or wash-outs in the yard between the skimmer and the pump.
Anyone have any ideas?