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staining information
Surface Staining
THE PROBLEM:
Dissolved metals and minerals are present in every swimming pool. These dissolved solids find their way into pool water in a number of ways: Fill water from wells or from city water lines can deposit dissolved minerals into the pool. Galvanized pipes and bronze or copper fittings in pool pumps and heaters are sources of iron, copper, and manganese. Foreign objects, from bobbie pins to pine needles, leave behind trace metals and minerals. Evaporation removes water from the pool, but leaves minerals behind, gradually raising the pool water's total dissolved solids level. Over time, these dissolved solids will precipitate, or "fall out" of the pool water, and settle into the surface of the pool. The resulting rust orange, brown, grey, and light blue-green stains are unsightly, and detract from the beauty of your swimming pool.
THE OPTIONS:
Among the options available to the homeowner are the following: Periodically draining and acid washing the pool surface. Mechanically removing minerals before they have a chance to deposit on the plaster. The type of filter required to remove minerals and heavy metals is called a nanofilter. It will clean the water to "bottled water purity" without having to drain water from the pool. Once the pool water has been cleaned with the filter, a chelating agent can be used to maintain the water in a "soft" condition. Chemical treatments, which remove minerals before they have a chance to settle on the pool surface on the plaster. These chemicals are called chelating agents. Their name comes from the Latin word for "lobster claw." Chelating agents "pinch" dissolved metals and minerals, holding them until they can be strained out of the pool water by the filtration system. Chelating agents are also known as sequestering agents.
THE BENEFITS AND THE DRAWBACKS: Draining and acid washing the pool will eliminate many stains, but it also accelerates pool plaster disintegration. Done by untrained or incompetent technicians, acid washing can lead to irreparable damage, from etching or pitting of the pool plaster to cracking of the pool shell. The cost and quality of acid washing vary tremendously. Charlotte and Sarasota county area pool companies typically charge between $975 and $1250 for an acid wash! Since there is little regulation of the pool repair industry, you can't always be certain of the competence of the crew performing the acid wash -- the less expensive companies may actually provide the highest quality service! Whatever the cost, you must pay the expense of draining and refilling the pool, which typically runs in the $100's range. Acid washing removes stains by dissolving a thin layer of pool plaster. The sort-term result is whiter, cleaner plaster, but the long term effects -- rougher, more stain-susceptible plaster There are a variety of chelating agents on the market. Whatever stain prevention treatment you choose, there are costs involved. For example:
Acid washing Wet/Dry
Regular maintenance is the best prevention against staining. Regular use of a chelating agent will prevent stains; preserve the appearance of your pool, and save the headaches and risks associated with nonfiltration and acid washing. Some surface discolorations are not stains at all, but result from flaws in the pool plaster.
