I was at my local lowes store and noticed that they had clearanced all their Clorox 10% liquid chlorine. It was marked down from almost $5 to $1.50. This seems like a good deal and wanted to know if anybody knew why they would mark it down so much.
Big box stores clear stuff from a previous season just to get it out of their hair. Chlorine degrades due to time and method of storage (i.e. the hotter the quicker it degrades).
Here is somehting epro05 posted back in August that may help you determine the age.
I thought the information below might be helpful for some of the forum participants.
I recently bought 1 jug of 10% Liquid Chlorine that was actually 4.5%. It had a 2013 date code. I now am very careful to check the date code before I purchase.
I thought this might be a handy reference for checking bleach/liquid chlorine date codes. This decoder is for the brands that are available in my area. If you have other brands please add to this thread if you want.
Note: Further down I show an easy way to measure the strength of your bleach/liquid chlorine.
Bleach/Liquid Chlorine starts decomposing after it is manufactured. Check this link (http://www.odysseymanufacturing.com/about_product.htm)(scroll down) to see the half-life table (half-life means half of the original strength). Note that decomposition occurs faster for higher strength chlorine and faster at higher storage temperatures.
As shown in the chart at the bottom of this page, bleach at 6% is going to last quite a while if kept at room temperature with it's half-life extending well beyond 2 years. Even high-quality chlorinating liquid kept at room temperature is going to be reasonable at 3-6 months, but if temps get warmer such as storing the chlorine outside in a shed, then the chlorine will degrade much more rapidly. Basically, 6% bleach lasts around 4 times longer than 12.5% chlorinating liquid, all else equal.
In practice, 10-12.5% chlorinating liquid is something you want to use within 3 months if you can and you don't try and store it for a year unless you keep it quite cool. Bleach can be stored and used even after 1 year if kept at room temperature. This all assumes high-quality product as the rate of degradation becomes much faster than shown in the table if there are metal ion impurities present such as iron, copper, cobalt, zinc, etc.