Pakistan's natural resources range from natural gas reserves, vast land, coal, petroleum, copper, salt and iron ore among others. It has the second largest salt mines in the world, as well as worldâs fifth largest gold mines.
Leslie's 14427 Hardness Plus, 25 lbs. Leslie's 14428 Hardness Plus, 45 lbs. Keep your calcium hardness at proper levels at all times to help protect your pool, water, and pool equipment. The calcium hardness level in a pool does not increase rapidly, but it is good practice to check the calcium hardness every month. Adding 1-1/4 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.
In swimming pools, calcium carbonate is normally added during routine pool water maintenance to increase pH, increase calcium hardness, maintain total alkalinity, and offset the acidic properties of disinfecting agents like chlorine or bromine.