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.
Calcium content is best in the range of 100-400 ppm and is water temperature dependent. Unlike pH or total alkalinity, however, both of which can be raised or lowered with reasonable ease, calcium levels cannot. Adding a hardness increaser to the water easily raises calcium levels. Conversely, there is no simple chemical addition that can be made that will reduce calcium hardness. The only way to reduce calcium hardness levels in pool water is through dilution with water of a lesser hardness.