Nuclo Basic Calcium Hardness is 100% Calcium Chloride Dihydrate. It is extremely fast dissolving, pH neutral and is pre-dissolved in water before adding. Having just the right amount of calcium is essential to the health of your swimming pool.  Too little calcium will erode plaster, cause etching of pool surfaces, and accelerate corrosion. The ideal range for calcium hardness is 200 to 400 ppm. 
 
NOTE: Minimum amount per order must be $20+ or surcharge will be applied. A minimum order of $20 will also qualify you for FREE Local Delivery.