My pool is about a year and a half old now and I finally bought some of those nasty chlorine tablets. I am almost out of the supply that the builder included and am about to head out for a vacation. I didn't have enough of them left to last the week. It felt strange buying them, sort of like I was doing some thing dirty. A 20lb bucket should last another year or two if everything goes well. Oh well, my cya was getting a little low anyway.