In many parts of the country the cheapest chlorine you can get is the PoolBrand dichlor 50# bucket for about $105. I just got the last 3 buckets at my local store this AM, because we're draining a local country club's pool after a storm broke 3 glass tables in both their main pool and their kiddie pool.

With a 50K gallon pool, 50lbs of dichlor is about 66 ppm of chlorine and 60 ppm of stabilizer. If your water is CLEAN and has no particular chlorine demand, that should last you about a month, and give you time to come up with something else. I'm not sure what part of Illinois you're in, or what your swim season is like.

But, with a 50K gallon pool, your probably want to see if you can get a 100# container of cal hypo. If you were just now starting the season, you could probably do very well with a 50# of dichlor, a 100# of cal hypo, 4 - 8 gallons of muriatic acid, and possibly a few boxes of borax. Depending on what's in your well water, you might need additional chemicals to manage that.

But, if you've been getting your advice from a pool store, it's no surprise you've had problems for the last 5 years. Pool chemical companies are desperate to keep up sales, in the face of losses to Asian chemicals, to SWCG's and to their on predatory treatment practices. As a result, their chemical recommendations have gotten 'goopier' and 'goopier' with more and more emphasis on high margin, low function, specialty chemicals.