Hey guys, I'm usually pretty good at math, but the different concentrations here are really messing me up for some reason... I'm hoping you can help! I've been maintaining my new pool for about a month now, and I just finished off my 3rd jug of Clorox. I pay $8.49 for a box of 3x 182oz jugs of 6% Clorox. It seemed like a good deal to me until I went to my local Pinch-A-Penny today to pick up a floating thermometer. They had 2 palettes of 10.5% liquid chlorine in 2.5gal jugs on hand. I asked one of the people there who seemed to be the manager about it. He stated that they sell the jugs for $7.50 plus another $4.50 for the chlorine inside. Once you empty the jug, you bring it back and subsequent fills are $4.50, with every 13th jug being free. I inquired about the freshness of it, and he stated that what they had on hand was delivered yesterday morning, and they get 2000gal delivered 5 times a week. Assuming I haven't yet confused the heck out of you, which do you think would be the better deal?

Costco = 546oz of 6% for $8.49

Pool store = 320oz of 10.5% for $4.50 after $7.50 jug purchase, buy 12 get 1 free

I may be way off here, but if I divide 6 / 10.5, I get a ratio of 0.5714. I assume that if I multiply 546oz by 0.5714 it will give me the equivalency of 10.5%, so that 546gal of 6% becomes 312gal of 10.5% equivalent. Does that make sense to anyone else or am I way off base? If my calculations are correct, it would be about half the cost to get a jug every month or so from the pool store. Thanks for reading my rant, please discuss!

Jose