Quote Originally Posted by brent.roberts
It has been frequently reported on this forum that the 12% stuff was unstable and I had a discussion with the manager of a local pool store manager and he readily admitted the degredation is a problem. He has 2 small ( 5000 litre ) tanks and gets weekly small deliveries so he can control his stock on a first-in first-out basic. Keeps it fresher than one 10,000 gallon tank where new stuff gets mixed with old stuff.

There is a chemical engineer type here who worked at a chlorine production facility and posted recently. I hope he sees this thread and can cite some more authoritative sources.

YUP, we at one time looked at making high strength bleach (this is back in the 1980's) and decided against it because of the degredation issues. You typically use a nickel or iron catalyst in the bleach production process and trace metals that remain in the bleach cause it to rapidly break down. So, you are best to stick with 6% or lower bleach - as you know that you will actually be getting what you pay for.

As far as the temps in Canada, Montreal can actually be hotter at times in the summer than NYC!