Expert Advice on Water Care
Q. My new pool is designed with a narrow patio on one end, with the lawn just a few feet from the water's edge. Do I need to be concerned about chlorine harming the grass?
No. The amount of chlorine in pool water is similar to the amount of chlorine in drinking water. Since drinking water is used to water the grass, the traces of chlorine should not be a problem. There are only 1 to 4 parts of chlorine per million parts of water. Often, the bigger issue when landscaping is near the pool is that soil, fertilizer and grass clippings get into the pool. If a proper chlorine level is not maintained at all times, these contaminants can promote the growth of algae in the pool. Many people use preventative algicides in addition to the disinfectant (chlorine) in the pool water to reduce the possibility of an algae bloom.
Q. I can smell chlorine, but my pool water still looks cloudy. What's the problem?
When you take a bath or shower, do you smell chlorine? The form of chlorine that is supposed to be in water to kill and inactivate viruses, bacteria and algae doesn't have an odor. When we smell "chlorine" it's a clear sign that there are contaminants in the water. One contaminant -- ammonia -- binds to chlorine to make a chloramines, and it's the presence of chloramines that causes "chlorine smell." In addition to the odor, chloramines are not effective at killing bacteria, algae, etc.
Advice: Test the water's "free chlorine" and "total chlorine." Subtracting the "free" level from the "total" will give you a "combined chlorine" measurement, the level of chloramines in your pool. This number should be below 0.5 ppm -- and the lower, the better. When chloramines are present, you can destroy them by adding a large dose of an oxidizer, shock or chlorine product. A water clarifier also helps to keep water clear. Remember to follow label directions to make sure the product is effective. Also keep close tabs on disinfectant levels (chlorine) and pH, and periodically clean or backwash your filter.
Q. My pool has new algae growth, but I hated the foaming that occurred last time I used algicide. What can I do to stop the algae?
The most common algicides do cause foam when they are added to the pool water and the water is agitated. But there are several "non-foaming" algicides available. Your pool supply professional can guide you to these products. Some non-foaming algicides have copper compound as the active ingredient; others use a polymeric quaternary algicide called "poly quats."
The bottle label should list the active ingredient and note that it kills algae and is a "non-foaming" product. The bottle should have an "EPA Reg. No." and an "EPA Est. No." that shows it has been approved by the U.S. Environmental Protection Agency for use as an algicide.
Thomas M. Lachocki, Ph.D., is CEO of the National Swimming Pool Foundation® (NSPF®). He earned his doctorate in chemistry from Louisiana State University and has been awarded six patents that are practiced in eight countries. In addition to expertise in recreational water care and chemistry, he has researched and published data on detergents and solvents.
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