Proceed with caution
Any water sample troubled with algae or high chlorine demand should be tested for nitrate levels to better understand the best control and treatment options. By overlooking nitrates, pool professionals can cost customers extra money and put their own reputations on the line. By letting clients know when a nitrate issue is present, they will be prepared for the extra chlorine and possible algae issues that might arise, even when normal parameters appear to be balanced. Nitrate testing can be the difference in being renowned as an expert or as the company that used to be trusted for swimming pool maintenance advice.
| THE NITRATE-PHOSPHATE CONNECTION |
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| Phosphate is a close relative to nitrate in swimming pool water. While they are very different chemically, they do come from common sources and have a similar affect on algae growth. Like nitrates, phosphates can also be introduced through fertilizer, human contaminants and source water. Phosphates also serve as algae food, providing essential nutrients for its growth and development. However, the big difference between nitrates and phosphates is that phosphates can be treated and removed through recent advances in modern chemistry—and these treatments may also hold the key to controlling high nitrate nitrogen levels. When chlorine is stressed and reduced due to certain factors (e.g. high bather loads, extreme heat, rain, etc.) or nitrates increase chlorine demand, nitrates and phosphates work together to feed algae; however, if the phosphate is taken away using phosphate-removal chemicals, the problem is greatly minimized. Algae needs phosphate to grow— without it, the problem is under control, if only temporarily. |
Joe Sweazy is technical sales and services manager for HACH Company/ETS Business Unit, manufacturer of AquaChek®, TruTest® Digital Test Strip Reader, FastChek™ Pro Prescription Testing System and other water quality products. He has published dozens of articles on pool and spa water chemistry and has presented numerous seminars at conferences of the Association of Pool & Spa Professionals (APSP), Northeast Spa & Pool Association (NESPA) and the World Aquatic Health™ Conference (WAHC). He may be reached at jsweazy@hach.com.
