Your cart is empty.
Your cart is empty.This product is used to increase the calcium hardness in spas and hot tubs with low levels of hardness. Low hardness levels will etch plaster and corrode equipment. Before adding this product, test the water with a calcium hardness test kit or ask your local spa dealer. The ideal hardness level is 200-400 ppm (parts per million). 1 ounce of product per 500 gallons increases hardness by about 10 ppm. 1. Determine amount of product to be added using a calcium hardness test kit. 2. Pour proper amount into spa or hot tub with equipment turned ON. 3. Run filter for 1-2 hours. 4. Water may be retested in 20 minutes.
Charlie W
2025-08-22 09:58:58
I use this for my outdoor hot tub, it performs exactly as described.
Janet
2025-07-11 13:51:53
We needed to increase the hardness of our swim spa and this is working well.
Duane Vipond
2025-06-04 14:54:35
Repeat purchase very satisfied with this product
Juan Orlando Vargas
2025-04-29 17:23:26
Good for the money
Holly E. Crawford
2025-04-11 17:58:00
Products did exactly what it supposed to do to do. It didn’t need another application once it was at the correct ppm in the water.
ERNESTO DEL CASTILLO
2025-04-10 11:15:01
Calcium level in swiming pool .
David B
2025-02-03 15:40:20
I have had good success with this brand and their products.
Customer
2025-01-05 15:20:28
Great product
Recommended Products
