I stopped by the pool store, picked up a new gauge and 4 Gals. of 12.5% chlorine. He said the stuff from Rural King at 10% is no good, probably more like 5-6%. I guess we'll see.
The stuff from RK is great. It works out as 11% when I've tested it.
You can get 12.5% for a reasonable price at Menard's when they have it on BOGO, but that is usually pre-Memorial Day. I have a bunch in my basement I got when they had the sale. When it's not on sale it is overpriced by a long shot. Stick with the RK stuff. Nothing else is close to the same deal, even when it is $7.99.