Chlorine question

[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.