Friend has a new home with a pool. Previous owners used EZ Pool. I am helping them learn pool care. Their pool will not hold chlorine. The have been exchanging water and have their CYA down to 95. They are adding 12.5% liquid and can’t hold chlorine over 1. They are targeting FC 11. Is there something in EZ that will hinder chlorine e holding? No algae is seen bc of the high amount of copper in the ez Pool.