I'm not 100% sure yet that there is a crack at the bottom of my pool, but all signs are pointing that way. I had a great leak detector guy come out yesterday who checked all the plumbing, lines, lights, coping, tile, deck, and even swam around the entire pool for about 30 minutes looking for a leak with dye. He didn't find anything, but did rule out everything except a hairline crack that could have been missed from being so small. I'll be draining my pool shortly to help spot the problem, but just thinking in advance, what are my options for fixing a crack that is leaking about an inch of water a day?