What it does...
hth Hot Tub pH Increaser (Soda Ash) is used to raise the pH level in hot tub / spa water. pH is a measure of how acid or how alkaline (basic) the water is. Low pH can lead to skin or eye irritation and corrosion of equipment. You need to raise the pH if it is below 7.2.
This product is a direct replacement for Fi-Clor pH Increaser