Robelle Pool Calcium Up granular calcium chloride 25 lb — raises and stabilizes hardness, dissolvable formula

Robelle 25-Pounds Premium Pool Calcium Up is a granular calcium chloride treatment designed to safely raise and stabilize calcium hardness in swimming pool water.

Low calcium hardness can cause etching, staining, or cloudy water and may accelerate wear on pool finishes and equipment. Robelle Calcium Up supplies concentrated calcium chloride in an easy-to-dissolve granular form, letting pool owners correct calcium hardness to recommended ranges for vinyl, tile, fiberglass, marcite and painted surfaces. This product is made in the USA and includes dosing guidance so you can add only what's needed based on your test kit results.

How do I know when to use Robelle Calcium Up?

Test your water with a trusted calcium hardness test kit. If your calcium level falls below the recommended range for your pool surface, use Calcium Up to bring levels into the target window and protect surfaces from damage and corrosion.

• Vinyl pools: 200–300 ppm recommended.
• Tile/exposed aggregate: 200–400 ppm recommended.
• Marcite, fiberglass, painted: 250–400 ppm recommended.
• Use the included chart to calculate pounds needed by pool volume.

What is the correct way to add this granular calcium chloride?

Dissolve the granules in a plastic bucket prefilled with pool water before pouring; never add dry granules directly to the pool. Pour the dissolved solution slowly around the pool perimeter while the pump is running to aid even dispersion and avoid localized high concentrations.

• Fill a plastic 5-gallon bucket with pool water; add up to 2 lb product per bucket.
• For a 10,000-gallon pool, do not add more than 10 lb every two hours.
• Keep circulation running during and for at least 30 minutes after application.
• Allow time between repeat dosings and retest before adding more.

How much will one dose change my pool’s calcium hardness?

Robelle Calcium Up is concentrated so small measured amounts produce noticeable changes. Use the product chart and your pool volume: for large pools add incrementally and retest to reach the desired ppm without overshooting.

• 8 ounces raises calcium hardness about 10 ppm in 5,000 gallons.
• Dosing calculators or the included chart speed accurate measurement.
• Add gradually and confirm with tests before repeating doses.

Is there anything to watch for after adding Calcium Up?

After treatment, retest calcium hardness and check pH and total alkalinity because changing calcium can slightly affect overall balance. Store product dry and sealed, and avoid contact with metals or corrosion-prone surfaces when handling concentrated solutions.

• Retest hardness after full circulation to confirm target ppm.
• Monitor pH and alkalinity and adjust as needed for balanced water.
• Use protective gloves when handling concentrated solutions and rinsing buckets.

Who this is for: Robelle 25-Pounds Premium Pool Calcium Up is for pool owners, service professionals, and maintenance teams who need a reliable, made-in-USA calcium chloride to raise total hardness. It’s especially useful when test kits show low calcium for vinyl, tile, fiberglass, marcite or painted surfaces, and for anyone who prefers granular dosing that dissolves quickly and disperses evenly through pump circulation.