Phosphate Chemicals

How Phosphates Impact Pool Water

There are many items to keep track of as a swimming pool owner. Two of them are phosphates and nitrogen; elements that are naturally occurring in nature. When found in nature, they do not necessarily lead to any problems, but when they are added to your pool water there is the potential for problems.

Perhaps you wonder, how phosphates impact pool water, and what about nitrogen? We have answers for you.

What are phosphates? 

If your swimming pool is close to trees and other organic plant life, phosphates from dead and decaying organics can upset the chemical balance in your swimming pool. Lawn fertilizer can also be a culprit as these organics can become windborne and get deposited into your swimming pool. When you have a combination of fertilizer, bugs, leaves, pollen or other items that may decay in the water, they can be sucked into the filter and eventually break down into phosphates. In addition, cells, laundry detergents and perfumes and oil can break down and lead to the growth of phosphates in the water.

Before our service technicians do anything to address phosphates in the water, it will first be tested to determine the levels in the water. Following a test, he will add a product to remove the phosphates – be advised that this could turn your water cloudy while it’s working. After the product has been added, he will monitor the pressure of your pool filter and adjust as necessary. The process to bring phosphate levels in balance may take several attempts to bring it back to less than 100 ppb.

Be aware though, that we may add phosphates (phosphorous) as a way to remove heavy metals from the water and they are found in chemicals that are used to control any staining of the pool deck or liner. 

What is nitrogen? 

Lawn care products can also be a source of nitrogen that makes its way into your pool, but again it can be introduced through human sweat, urine or other ammonia sources. If the supplier of your water uses chloramine to sanitize your drinking water, you may find that large amounts of ammonia are making their way into your water (especially if you find yourself filling it frequently).

Algae thrives on phosphates and nitrogen. Even if your pool testing finds levels of phosphates or nitrates in the water, it is not as much of an issue as long as chlorine and bromine levels are correctly maintained. If the chlorine is “stressed” because there are more swimmers in the pool than usual or if there was a recent rainstorm, you could see chemical levels worsen and algae take hold.

What will we do to address the issue? There are several steps:

  • Work to maintain good water balances
  • Assure that there are proper levels of bromine or chlorine residuals in the water
  • The pool will be shocked, and an algaecide will be added – usually weekly
  • We suggest a twice a year chlorine demand test be taken and if he finds that chlorine demand exists, he will suggest treatment
  • Institute a “shower before you swim” rule

When you purchase a maintenance package, these are issues with which you will likely not be faced, but it’s always best to be an informed consumer.

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