Dry acid is a chemical used to lower the pH and alkalinity of pool water. It is also used to remove scale, rust and other deposits from pool surfaces.

Dry acid is usually sold in granular or powder form. When using dry acid to lower the pH and alkalinity of pool water, it is important to follow the manufacturer‘s instructions carefully.

Once the desired pH level has been reached, it is important to test the pool water regularly and adjust the amount of dry acid as needed. If the pH level begins to rise again, more dry acid may be needed.

Dry acid can also be used to remove scale, rust and other deposits from pool surfaces.