First of all, yes I did do a search and found some old posts but thought I'd throw this out there again. My Hayward CL200 Automatic Chlorine Feeder needs its O-Ring replaced about 3 times a season. I live in NY, and have a 25,000 gallon inground. I've tried original Hayward rings, and secondary market rings, with lube and without lube, from a pool store, pool supplier online and bags of 5 from eBay. I really haven't hit a combination of things that make the ring last the season, let alone more than one season. What's the current theory behind o-ring longevity? Thanks, Dave