Pool Mate 25-Pounds Premium Calcium Hardness Increaser for Pools – 100% Calcium Chloride

Maintain balanced pool water by increasing calcium hardness with Pool Mate 25-Pounds Premium Calcium Hardness Increaser. This dry, granulated formula uses pure calcium chloride to raise total hardness and support a stable, comfortable swimming experience. Use with a trusted test kit to determine the right target for your pool surface type and to guide dosing.

Why calcium hardness matters

Calcium hardness helps protect your pool surfaces from corrosion and etching by maintaining the mineral balance. Depending on your surface—vinyl, tile, plaster, fiberglass—the recommended range varies. With Pool Mate, you can aim for the appropriate range and monitor changes via test measurements.

What you get and how it works

This product is designed for quick, visible changes in hardness. A little goes a long way: 8 ounces raise hardness by about 10 ppm in roughly 5,000 gallons. The included dosing guidance shows how to apply in steps.

• Calcium chloride for pools
• Rapidly increases total hardness
• Helps prevent corrosion or etching of pools
• Ideal calcium hardness range 200 - 400 ppm
• 8 ounces raises calcium hardness level 10 ppm per 5,000 gallons of water
• Prevents the staining or etching of your pool's surface
• Low calcium hardness level can cause water issues

Usage guidance and real-world tips

Follow the included chart and use a bucket method for safe mixing. Steps typically include dissolving the product in a bucket of pool water and distributing the solution around the pool while the circulation system runs. For larger pools, pace the dosing to avoid rapid shifts. In a 10,000 gallon pool, avoid adding more than 10 pounds in a two-hour window.

• Test water first with a reliable kit
• Place the product in a bucket of pool water
• Pour slowly around the pool perimeter with the pump on
• Limit dosing to 10 pounds per 2 hours in a 10,000 gallon pool

By staying within target ranges, you may help support a balanced environment that feels comfortable for swimmers while maintaining surface integrity. This is a dry granular product designed for easy storage and careful use as part of routine pool maintenance.