Calcium is an alkali metal essential for life on the planet Earth, typically found dissolved in lakes, seas and oceans or in lime deposits on land. The fifth most abundant element in the crust of the planet, calcium is required to build shells, teeth and bones, and is the most plentiful metal found in animals such as humans.
In ancient times the most common form of calcium was lime, and it was used for buildings as far back as 14,000 BCE. While Ancient Romans created calcium oxide from natural lime deposits in the first century of the Common Era, the real breakthrough came in 1808 when Sir Humphry Davy isolated calcium, along with potassium, sodium, magnesium, barium and boron.
Being an alkaline Earth metal (metals that naturally dissolve in water), it's essential for swimming pool water to have a balanced level of calcium. The calcium range for the best pool water is between 250 and 350 ppm. Swimming pool water high in minerals such as calcium will form scales on the pool walls, in the piping and in the filters, clogging these systems, reducing the flow of water and decreasing the efficiency of the filter. Prolonged exposure to water high in calcium can cause a total system failure of a swimming pool. In the beginning, the water will become cloudy, causing swimmers to complain about irritations to their eyes and skin.
Swimming pool water low in calcium becomes caustic and acerbic and is harder to identify than water too high in calcium. Why? Unlike high calcium, which causes cloudy water, the effects of low calcium are typically observed over longer periods of time, slowly deteriorating your swimming pool. The water may feel slimy, and the chlorine may become ineffective, but you will no doubt notice the water has become corrosive, staining, scarring or biting into pool liners, pool ladders, pool fittings and anything metal in the pool water.
How do you address these issues with calcium? If calcium is too low, try Calcium Plus, a great product if your swimming pool water is too soft (pictured left is tub of Calcium Plus as an example; view Calcium Plus here). You typically add this solution by broadcasting it evenly over the pool surface; swimmers can jump in immediately, as long as the calcium levels reach the ideal range.
If the calcium levels are too high, fixing this problem can become problematic. You might have to drain some of the pool water and replace it with water low in natural minerals. Chances are the high calcium content comes from the water itself; well and some city water sources are notorious for water high in minerals. There is really nothing available to remove calcium from your water; our pool experts recommend when you are filling your pool to be sure to treat the water with a metal treatment such as Metal Free (view Metal Free here). Another way to help reduce the calcium is to avoid calcium-based Shocks and rely on sodium-based Shocks. If you find yourself with pool water high in calcium it's best to consult a pool expert or water utility expert.
Family Leisure can help answer your pool-related questions; visit any of our locations for swimming pool water testing, or give us a call at 877.775.3478 to have your questions answered over the phone. All of our pool supplies ship nationwide for free; view Family Leisure Swimming Pool Supplies here.