Well it did work... Our pool had been lovely but then after a swim party boom! So I have not shocked the pool weekly with Lithoshock as the pool Wearhouse says to do this summer. Although when we have in the past we never end uo with issues There was a green hue to the water that night and weve had the algae bloom overnight at times and I didn't want a replay of that. I have used liquid shock before as well when necessary and Afyerward "Pool First Aid". Here were my test results that night. Alk 160 ph 7.6 then 7.4 after acid. We have very hard water about 560 ppm out of the faucet. Usually acid is what we need more than anything. We've had this exact pool, liner and all for 9 years and have only had to empty it once due to lack of chemicals in the winter ONE year. Never again! Also we've had to drain the pool by about 1/3rd dur to stabilization lock issue, other than that tho we've kept same water year after year. We do not drain on a consistent basis. We always maintain the pool and leave the pump running non stop except some winters we will leave it on for only 4 hours a day using a timer...