Leslies Hardness Plus

Boost your pool’s hardness level with Leslie’s Hardness Plus. This 4 lbs. calcium hardness increaser protects your pool and equipment, while adding 10 ppm to 10,000 gallons of water per 1-1/4 lbs.

Product Description

Keep your calcium hardness at proper levels at all times to help protect your pool, water, and pool equipment with Leslie’s Hardness Plus, 4 lbs.
Calcium hardness increaser
Keeps your pool and equipment free from damage
Increases Calcium Hardness by 10 ppm per 1-1/4 lbs. in 10,000 gallons of water.

Available Options


The calcium hardness level in a pool does not increase rapidly, but it is good practice to check the calcium hardness every month. Adding 1.25 pounds of hardness plus to 10,000 gallons of water will raise the calcium hardness by 10 ppm. **The minimum level of Calcium Hardness is 150 ppm.


1.25 lbs per 10,000 gallons