Absolutely great price! Even cheaper than a discount store I have been buying from. (First time seeing at Sam’s). If you have a vinyl pool this is what to use, as Cal Hypo can damage liners. And for the reviews that complain about CYA (chlorine stabilizer) chlorine block is a myth, all types of this chlorine contains stabilizer, so it is no different than any other that is out there. Oh and of course it’s ground up chlorine, what else is it supposed to be?

This is NOT CYA free. I used and it made my cyanuric acid levels skyrocket. I had to drain my pool to get rid of this product. Too much CYA causes chlorine lock which means you keep dumping it in your pool and it does nothing. You’ll have green water and high phosphates in no time. I highly suggest avoiding this product and buying CYA free product.

This product is not effective. The only time we've battled algae is when using this as the weekly shock treatment rather than liquid shock. We even cycled back to trying again (since we have an entire bulk box of it) once we ran out of liquid shock, and had algae again within 3 days.

Though they don't list it, this shock contains cyanuric acid. If you're just doing a weekly maintenance dose it works fine. If doing a higher dose it runs your CYA numbers through the roof.

I have used it in the past. I believe it caused chlorine lock because it raised my Cyanuric acid and I had to drain almost a whole pool.

The prices are still to high for the pool products

This is a terrible. Using this product raised the CYA. We had to empty 1/2 of the pool. they should have to reimburse us for the chemicals and water. Do not buy this product.

If you want to drain your pool later due to high CYA levels caused by using cheap stabilized shock then this is for you. I made the mistake of using this and now I’m paying the price. Do yourself a favor and use Cal-Hypo shock. I’ve bought this shock twice now and my CYA is 148. Gotta drain and start over.

DOES NOT WORK LIKE NAME BRANDS. DONT WASTE YOUR MONEY

my pool is still green after shocking. chlorine is high but doesn't clear. i had already cleaned the pool and it turned green again idk. hadn't had this problem in the past. haven't had good experience with this product.