For our Inground pool 25k gallons, Michigan. Saves money initially but if it doesn't work as well it's a big headache on down the road. Get real shock instead. Maybe works ok for above ground pool, don't know.

I didn’t believe the other reviews with horror stories about green pools. I figured it was probably due to other issues and those people were just blaming the shock. I have never had a problem with algae in my pool and I only used this shock as part of my normal maintenance. We get a lot of rain here in Florida and after a week with a lot of rain I will use one bag of shock. I usually use Zappit brand sold my my local pool shop, but this was a significant savings. You get what you pay for. Within 24 hours the pool was cloudy within 48 hours I had greenish brown stains everywhere. I took a water sample to my pool shop and I didn’t initially tell them anything so they would give me an honest opinion of the water condition. They said the salt/chlorine levels, PH and stabilizer were all good and they wouldn’t recommend anything at the moment.I then told them about all of the green stains and that I had no problems until I used Sam’s shock. They were incredulous and said they’d never heard of shock causing this. After a 1/2 gallon of acid, an algacide and twice daily brushing for 3 days, we seem to be to getting the problem under control. Save yourself the grief and stay away from this shock.

I was all excited, I got a Sam's Club card, a new place for me to get swimming pool supplies. I have tried the Fast Dissolving Shock and unfortunately, it doesn't dissolve for me, it just sinks to the bottom of the pool. I have to use my brush to dissolve it. Maybe just an old box, i don't know....

10 out of the 24 bags were split open in the box.

This product stained my pool twice. It contains copper.. Buyer Beware!

We’ve always pool shock but a different brand and it works great. This stuff doesn’t work at all!!

This is a great deal...most of shock is going for $50 for a 6 pack and yes last year it was $60

I bought it last year for $60 now its doble the price. Considering having a pool its harder now.

Good product but in my box some packages are not sealed properly so turn bag to back side when taking out of box good luck.

Definitely not as powerful as other name brands...used the entire amount to get the same effect. Do not recommend despite the price.