Spa water deprived of calcium can become aggressive, etching surfaces and corroding equipment over time. This 750g spa water hardener (calcium chloride) raises calcium hardness to the ideal level of 200-300ppm, helping protect your spa and keep the water properly balanced.
As a guide, 10g increases calcium hardness by 10ppm per 1,000 litres. It is recommended to pre-dissolve the product in a bucket of water before adding to your spa, and treat dosage rates as a starting guide rather than an exact measure.
