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.
Cleaning. 1  1. Blast debris out of the pop-ups with your hose. If you have an in-floor cleaning system, this is a great option for you to use. 2  2. Clean away any calcium or scale rings. Now is also a good time to clean away calcium or scale rings (if any exist). 3  3. Perform an acid wash on your pool (optional).