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.
Add the acid to the bucket and pour it slowly around the deep end of the pool. If you are adding a large quantity of acid, do it in stages - DON'T add large amounts of acid to the pool at one time. Allow the pump to circulate the water for at least 4 hours and then test the pH again. A pH reading of 7.0-7.6 is required, with 7.2 being the ideal level. If you add too much acid to the pool at one time, you risk etching the walls, corroding the pipes and pump fittings and you lower the total alkalinity of the water.