Pool Mate Calcium Hardness Increaser for Pools — 16 lb Granular Calcium Chloride, Fast-Acting Protection

Pool Mate 16-Pounds Premium Calcium Hardness Increaser is a granular calcium chloride formula designed to raise and stabilize your pool's calcium hardness to recommended levels quickly and reliably.

Maintaining proper calcium hardness prevents surface damage and water chemistry imbalances in your pool. This dry granular product dissolves in water to safely increase total hardness so vinyl, tile, fiberglass, painted, or marcite pools remain protected. Use a dependable test kit first, then follow the dosing guidance to add no more than recommended per period and always dilute the product in a bucket of pool water before introduction.

How do I determine if my pool needs calcium hardness added?

Test total calcium hardness with a reliable test kit. Compare the reading to the pool-type ranges provided: vinyl pools generally need lower levels than exposed aggregate or tile pools, and some finishes require slightly higher hardness to avoid damage.

• Vinyl pools: 200–300 ppm
• Tile/exposed aggregate: 200–400 ppm
• Marcite/fiberglass/painted: 250–400 ppm
• Add product only when tests show values below the target range

What is the correct way to add Pool Mate calcium hardness increaser?

Dissolve the measured granules in a plastic bucket filled with pool water before introducing to the pool. Add slowly around the pool perimeter while the circulation system is running to promote even distribution and avoid local high concentrations.

• Pre-dissolve up to 2 pounds per 5-gallon bucket of pool water
• Pour solution slowly around the pool with pump running
• In a 10,000-gallon pool, limit to 10 pounds per 2-hour period
• Wait after adding, then retest before further treatment

How much product changes my pool’s hardness and how fast?

Calcium chloride raises hardness quickly once dissolved and circulated, so you’ll see results after the water has fully mixed and been retested. Use the dosing chart included with the product to estimate the pounds required for your pool volume.

• 8 ounces raises hardness about 10 ppm per 5,000 gallons
• Calculate pounds needed from your pool’s gallon volume and current ppm deficit
• Add gradually and retest to avoid overshooting the target range

Will this prevent damage to my pool surfaces?

Keeping calcium hardness within recommended ranges reduces the risk of etching, staining, and corrosion associated with low hardness. This product helps stabilize the water so surface materials remain protected when paired with balanced pH and total alkalinity.

• Helps reduce corrosion or etching of plaster, tile, and metal fittings
• Prevents staining and surface degradation linked to low hardness
• Works best as part of routine water balance maintenance

Who is this for: Pool Mate 16-Pounds Premium Calcium Hardness Increaser is suited for pool owners, service professionals, and facility managers who routinely monitor water chemistry and need a fast-acting, measurable method to raise calcium hardness. It’s appropriate for residential and commercial pools with vinyl, tile, plaster, marcite, painted, or fiberglass finishes when test results indicate calcium hardness is below recommended levels. Always follow label directions, dilute before adding, and coordinate with overall water balance practices to protect your pool and equipment.