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 Member's Mark Pool Shock makes our pool look crystal clear. For our pool 2 Packets at a time

Works as advertised. Priced fairly. I'll buy it again.

Better than Leslie's over priced shock!

Just as good as the pool supply store, for less!

Worked really well going by recommended amount. Great deal when on sale otherwise just average price like everyone else.

Really good shock. I switched to these and I only have to add 1/2 as often now. 1 a week and it holds the chlorine levels.

easy to use and swim 15 min. later

Works great, the boxes I purchased before came with test strips. I was disappointed that these didn't this year even though they cost the same.

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.