Bleach Shelf Life In Heat?

[Z7What]

I get my bleach from a friend of mine. I get a 5 gallon jug at a time and its 12-15% per the label. Because its a large jug I keep it in my shop in the back yard. It gets pretty hot in it but nothing crazy due to having a 16" exhaust fan that runs off a thermostat that I keep at 90*. Once it comes on it pretty much stays on all day but does pull a good about of air through the small shop. I know its said for bleach to be store at room temp but its just not practical to bring it back and forth to inside the house. Should I expect the strength to weaken before using it all?

When using Pool Math I always enter 12% even though it has a possibility of being 15%.

Wayne

 

[Richard320]

This chart shows the half life of bleach. I stole the link from one of chem geek's threads. There may be other threads somewhere that has a better graph. You'll have to wade through the search results yourself.

 

[chem geek]

This post gives more details for breakdown of 8.25% bleach and 12.5% chlorinating liquid as a function of temperature, though actual breakdown rates depend on the quality of product. These charts show high-quality product (i.e. no metal ions in them that catalyze breakdown; also they have an appropriate amount of excess lye in them for higher pH that reduces the breakdown rate).

At 90ºF, 12.5% chlorinating liquid will be a little less than 11% in a week, 10% in 2 weeks, and about 8.4% in a month.