CPF 1kg Calcium Hardness Increaser, Calcium Chloride for Hot Tub & Swimming Pools, Help increase Calcium Levels

Perfect for treating my water for hot tub use.

Increased water hardness to correct levels after 2/3 doses.

I'm new to hot tub management, glad I know a bit of chemistry and have a good set of weigh scales. This does what is required. I've found it best to put it in a jug of hot water before adding to the pool.