Chlorine question

[waldreps]

I found a good price on some 12.5% liquid chlorine but it's in clear gallon jugs. Will the lights from the store or anything degrade the chlorine since it's in clear jugs? Also, if kept inside, does chlorine degrade over time like if I have some left over from season to season?

Thanks,
Stacy

[AnnaK]

Chlorine concentration does degrade over time. It ap[pears to be related to temperature. Here's a link: http://www.odysseymanufacturing.com/about_product.htm. At the bottom of that page is a link to shelf life of chlorine at different concentrations.

I buy liquid chlorine which is said to be 14% when manufactured. I've tested it a couple of times and have come up with something between 10 and 12%. I use 11% when I calculate how much to add to my pool. When I have chlorine left over at the end of the season I don't actually care what strength it is at startup. I just pour in what's left because I know the pool will be at 0 FC.

[waldreps]

Thanks for the reply. I should probably buy one and test it to get an idea about it's strength before buying a bunch of them. They normally have this priced at $3.99 per gallon but now have it on sale at 4 for $10. I'm guessing at $3.99 per gallon they don't sell a lot of it so it's probably been sitting there for a long time.

[AnnaK]

Being a cynic I would have to agree. A drop fro $3.99 to $2.50, which is less than a gallon or regular bleach, likely means it's old-y and moldy. Testing bleach to get its actual concentration can be a bit of a PITA. You can use the shot glass method and get an approximation, or you could just buy a gallon, test your pool before you put any in, put in 2 quarts, and test again after a couple of hours. If you're using a DPD-FAS test kit you'll get a good idea of the strength of this bleach. Just be sure to read the label: you do not want scented or gel'd or anything but sodium hypochlorite.

[waldreps]

Yeah, this is called Clear XTreme Pool Shock. The label says 15% available chlorine and 12.5% sodium hypochlorite. I'm assuming this would be considered 12.5% concentration. I'm not sure what the 15% available chlorine part means.

[AnnaK]

I don't either and I don't really believe an effective concentration of 12.5% at time of purchase. A quick Google search does seem to indicate it's a common bleach product sold for pools and listed by the EPA as Hypo 150. Menard's, a big box hardware store in the south, sells it for $1.99 a gallon if you have a coupon.

[waldreps]

This is at Menard's, but unless I'm mistaken Menard's is only in the Midwest. $1.99 per gallon would be an awesome price though.