I would only recommend this to someone with the abilty to vacuum to waste. I may have ruined the cartridges but that’s my fault for not reading everything first. It took a lot of vacuuming and cleaning of the filter daily over a week.

It did clear the water and drop all the debris to the bottom of the pool but getting it vacuumed out with the cartridges was a pain. I have a cartridge filter without the ability to vacuum to waste which is extremely important when using this product and should be in bold print on the front label. I bought and used this a month ago but neglected to read all the instructions beforehand. I’ve had this pool for 21 years and never had chlorine turn the water green until I used this product. Fight severe algae bloom and return your pool to its clear blue appearance with the HTH Pool Care Green to Blue Advanced Shock System for indoor and outdoor. It’s always blue again the next day but shows 0 chlorine.

Must Vacuum to Waste, Chlorine Turns Water Green I only gave 2 stars because now I have the problem of my water turning green for 24 hours every time I add chlorine.

Hth green to blue shock system