Pool Mate 32 lb Calcium Hardness Increaser for Pools — Granular Formula to Raise & Stabilize Hardness

Pool Mate 32-pound Calcium Hardness Increaser is a dry granular calcium chloride formula designed to safely raise and stabilize your pool's calcium hardness to the recommended range.

Maintaining proper calcium hardness protects pool surfaces and equipment from the effects of water that's too soft. This concentrated, easy-to-dissolve granule lets you correct low hardness without adding unnecessary water volume. Use a reliable test kit first to confirm your current ppm, then follow the product's dilution and application guidance to bring levels into the ideal windows for different pool finishes.

How quickly will this product change my pool's calcium hardness?

Results depend on pool size and how much product you dissolve, but the formula is designed to raise hardness efficiently when used as directed. For small adjustments, dissolving the correct amount in a bucket and distributing it around the pool while the pump runs is sufficient. For larger corrections, stage additions to avoid overshooting the target.

• 8 ounces will raise calcium hardness approximately 10 ppm in 5,000 gallons of water.
• Do not add more than 10 pounds to a 10,000-gallon pool within a 2-hour window.
• Dissolve product in a plastic bucket of pool water before adding to the pool.
• Circulate water during and after application for even distribution.

What levels should I aim for with different pool surfaces?

Different pool finishes require different calcium hardness ranges to minimize surface damage and staining. Vinyl typically requires lower hardness than plaster or exposed aggregate, while marcite, fiberglass and painted surfaces tend to need the highest recommended range. Test and adjust slowly to reach the appropriate window for your finish.

• Vinyl pools: aim for about 200–300 ppm.
• Tile and exposed aggregate: aim for about 200–400 ppm.
• Marcite, fiberglass, painted pools: aim for about 250–400 ppm.
• Use a reliable test kit to verify before and after treatment.

How do I apply Pool Mate Calcium Hardness Increaser safely?

Follow safe dilution and application steps to prevent concentrated product from contacting pool surfaces directly. Always mix the recommended amount into a plastic bucket pre-filled with pool water and pour slowly around the pool perimeter while the circulation system runs. Avoid adding large amounts all at once in smaller pools.

• Use up to 2 pounds per approximately 5-gallon bucket of water for mixing.
• Slowly pour the dissolved solution around the pool perimeter with the pump on.
• Do not apply undissolved granules directly to the pool finish.
• For significant increases, spread additions over hours and retest between doses.

Will increasing calcium hardness affect other water chemistry readings?

Raising calcium hardness can influence overall water balance but doesn’t directly change sanitizer levels. However, altering one parameter can affect scale formation or corrosion potential, so recheck total alkalinity and pH after treatment. Balancing all parameters helps the pool perform best and protects surfaces and equipment.

• Retest pH and total alkalinity after adjusting hardness.
• Adjust other sanitizers or treatments only if recommended by test results.
• Regular monitoring prevents scale or etching caused by imbalanced water.
• Use a complete test kit for accurate multi-parameter readings.

Who is this product for? Pool Mate 32-Pounds Calcium Hardness Increaser is intended for pool owners and maintenance professionals who detect low calcium hardness and need a reliable, granular solution to bring levels into the recommended range. It’s suited to backyard vinyl, tile, exposed aggregate, marcite, fiberglass and painted pools; best used by anyone comfortable testing water, diluting chemicals in a bucket, and following staged dosing guidelines for safe, even results.