Quote Originally Posted by ChuckD View Post
No offense cc, but I think that's pure conjecture. It's definitely not been my experience. Using the PoolCalc I can always predict the rise in Cl in my pool when it's added which pretty clearly shows that it's concentration is as advertised. This includes using an unopened 5 gal. bottle that sat in my unheated garage all winter. Measured Free Cl before adding, calculated the amount to bring up x amount and then after one hour of circulating measured again and all's going according to plan.

Do you have evidence Cl will degrade in a sealed container? It's volatile and will evaporate in the open air, but actually degrade?

C.
Well the evidence I have is I am a chemical engineer and used to work in a manufacturing facility that made the stuff. If there is the slightest amount of trace metals in the bleach (which their almost always is) high temp will cause it to degrade. Low temp in your garage will not impact it.