Robelle Pool Calcium Up granular calcium chloride 25 lb — fast-dissolving hardness increaser, USA-made for stable pool chemistry

Robelle 25-Pounds Premium Pool Calcium Up is a granular calcium chloride treatment designed to raise and stabilize total hardness in swimming pools to recommended levels.

Keeping pool calcium hardness within the correct range protects finishes, prevents corrosion and keeps water chemistry balanced. Robelle Premium Pool Calcium Up is a dry, fast-dissolving calcium chloride product made in the USA that lets pool owners precisely increase hardness when test kits show low calcium levels. Use it with your regular testing routine and follow dilution and dosing guidance for safe, even distribution.

How does Robelle Calcium Up correct low calcium hardness?

The product is a concentrated granular calcium chloride formulated to raise total hardness when added to pool water. It dissolves quickly when pre-mixed in a bucket of pool water, producing a clear solution you can safely pour around the pool perimeter while the pump runs for even circulation.

• Add to a plastic bucket filled with pool water — up to 2 pounds of product per 5-gallon bucket.
• For a 10,000-gallon pool, limit additions to 10 pounds per 2-hour period to avoid localized over-concentration.
• Always run the circulation system while adding the solution for uniform distribution.

What calcium hardness levels should I aim for in different pool surfaces?

Target ranges vary with pool finish because each surface reacts differently to mineral content. Use a reliable calcium hardness test kit and adjust the dose until your pool is within the recommended range for your surface type.

• Vinyl pools: aim for 200–300 ppm to protect liners from distortion.
• Tile and exposed aggregate: aim for 200–400 ppm to avoid staining and etching.
• Marcite, fiberglass, painted surfaces: aim for 250–400 ppm to preserve finishes.

How do I apply Robelle Calcium Up safely and effectively?

Pre-dissolving in water prevents concentrated granules from contacting pool surfaces and reduces cloudiness. Use plastic containers only, add gradually, and pour the solution slowly around the pool while the pump runs to ensure even mixing.

• Pre-fill a plastic bucket with pool water before adding the calcium chloride.
• Use up to 2 lb of product per ~5-gallon bucket; stir until dissolved.
• Pour the solution slowly around the pool perimeter with the filter operating.
• Wait and retest hardness after circulation before adding more; follow the maximum rate limits.

Will this affect other water chemistry or require special precautions?

Raising calcium hardness can influence saturation index and other balancing steps, so retest pH, alkalinity and hardness after treatment. Avoid adding large amounts at once; incremental dosing helps maintain overall balance and prevents scaling or cloudiness.

• Retest pH and alkalinity after adjusting hardness and correct if needed.
• Do not exceed recommended per-period additions for your pool size.
• Store product dry and sealed; keep away from moisture and incompatible materials.

Who is this for: Robelle 25-Pounds Premium Pool Calcium Up is intended for pool owners, service professionals and maintenance crews who need a reliable, made-in-USA calcium source to raise total hardness. It’s suited for vinyl, tile, exposed aggregate, marcite, fiberglass and painted pools when testing shows calcium is below the recommended range. Follow testing, dilution and dosing instructions to maintain balanced water chemistry and protect pool surfaces.