9 g per m³ lifts calcium 10 ppm. For a 40 m³ pool that is 360 g per 10 ppm.

Will it cloud my water?

Briefly. Pre-dissolve and run filtration 12 hours; cloud clears.

What range should I aim for?

200-300 ppm for plaster pools; 150-250 ppm for vinyl liner pools.

5 kg, 10 kg and 25 kg sacks of food-grade flakes.

How often do I need to dose?

Once per swim season for most pools, more often if you backwash heavily or top up from soft mains.

Yes, the same calcium chloride used in cheese-making and pickling; 77-80% purity.

What is the active ingredient?

Calcium chloride dihydrate at 77-80% purity.

Dissolving calcium chloride releases heat; pre-dissolve in 5-10 L of pool water for safety.

Will it add chlorine?

No. Calcium chloride contains chloride ion, not chlorine. No sanitiser effect.

Pre-dissolve next time; calcium precipitates briefly under high pH.

Calcium too high now?

Partial drain 25-30%; refill with mains water and retest.

Calcium chloride vs calcium carbonate?

Chloride dissolves fast and lifts hardness directly; carbonate is the scale form, not used as a dosing chemical.

Hardness increaser vs scale inhibitor?

Increaser lifts low hardness; inhibitor stops high hardness depositing as scale. Different problems, different chemicals.

Pool Calcium Hardness Increaser

Name: Pool Calcium Hardness Increaser
Brand: ClearSpa
SKU: pb-4
Availability: InStock
Rating: 4.5 (4 reviews)

Calcium chloride flake hardness increaser for swimming pools. Lifts calcium hardness 10 ppm per 9 g per m³ to stop soft-water corrosion of plaster, grout and metal heater elements.

Raises calcium hardness approximately 10 ppm per 9 g per m³.
Stops soft-water etching of plaster and grout.
Stabilises pH and stops sudden swings.
Cuts foaming on heavily aerated pools.
Protects bare-metal heater elements from leaching.