What are Nitrates and Phosphates?
Phosphorous is a mineral and Nitrogen is a gas. Nitrogen enters the water & combines with oxygen to form Nitrates.
How do Nitrates and Phosphates get into the pool water?
Phosphates come into the pool water from lawn & tree fertilizers (blown or rained in from you or your neighbors yard or on swimmers feet), well water, residual detergent/soap (bather’s swimsuits, shampoo, hair & skin products residue), or added directly to the pool in the form of metal removal and stain treating chemicals. In some areas, like NYC, SHMP (polyphosphates) is added to the public water supply to reduce pipe corrosion.
Nitrogen comes into the pool from bather perspiration, urine, human waste, cosmetics, or other types of ammonia (bird, pet and duck droppings).
Why can Nitrates and Phosphates be a problem in pool water?
Elevated levels of nitrates and phosphates can become a problem in your pool water. Phosphates and Nitrates are known plant nutrients and known pollutants. Algae loves both nitrates and phosphates. The two of them work together, and both must be present for the algae to feed. At the same time, when the nitrogen combines with the oxygen from the chlorine it causes a chlorine demand and you will have a hard time maintaining a Free Chlorine level. With this excessive chlorine consumption, the algae will bloom and your water quality will be poor (cloudy, green).
Do I need to worry about Nitrates and Phosphates in my pool?
Most pool owners do NOT need to worry about Nitrates and Phosphates in their pool water if they maintain good water chemical balance (Free Chlorine residual of 2.0 to 4.00ppm, pH 7.2-7.9, Total Alkalinity of 100 to 140ppm, Cyanuric Acid of 35 to 130ppm and Calcium Hardness of 175-300ppm) and have swimmers shower before using the pool.
How do I know if I am having a problem with Nitrates and Phosphates?
You are probably having a problem with Nitrates and Phosphates if you have the following symptoms:
Cloudy Green Water
Green or Mustard Algae growing on floor and walls
Excessive Chlorine Consumption – you are adding a lot of chlorine but not able to get a free chlorine residual.
Poor water quality
If you have these symptoms bring a water sample to your local pool professional for a phosphate test. If a Phosphate test by your local pool professional shows phosphate levels over 125ppb or .125ppm you will need to treat the water.
How do I solve the Problem?
Algae requires both phosphates and nitrogen to feed. Remove the food and you starve the algae. Since nitrates can only be removed from the water by draining and refilling with fresh water, chemical manufacturers focus on removing phosphates to resolve the issue. Use Orenda PR10000 OR Natural Chemistry’s Phos-Free, a natural, non-toxic mineral compound, to effectively reduce the phosphates in your pool without clouding the water. To maintain near zero phosphate levels treat weekly with Natural Chemisty’s Pool Perfect + PHOSfree. Follow the directions of your local pool professional to obtain and maintain good water chemical balance and the proper use of the phosphate removal products.