Phosphates In Pool Water: What You Need To Know.

So you've heard the debate and all the questions, right?  What about phosphates in my pool water?  What do they do?  Why are they there?  Do I need to get rid of them, and how would I do that?  Well, after being in the pool business for over 20 years and having cleared up over 700 green and nasty pools in 3 states, you're going to learn why I never used a phosphate remover to clear up any of my pools.  But first... 

What Are Phosphates?

Phosphates contain phosphorus which, in this application, is an inorganic matter that potentially feeds and encourages algae growth in your swimming pool.  Pool algae needs a perfect environment to grow and unbalanced pool chemistry offers that up.  It also needs a food source such as nitrates to flourish.  Basically, phosphates are the perfect food for pool algae. 

Phosphates In Pool Water: What You Need To Know.

Why Does My Pool Have Phosphates?

Phosphates can enter your pool through a variety of sources such as leaves, lotions, oils, skin and hair products, sweat, and the ever present fertilizer that is carried through the air.  Even some water municipalities add phosphates to our water to maintain a lower copper level and for other chemical reasons.

How Can I Test For Phosphates?

There are several ways to test for phosphates in our pool, but the most common ways are with test strips or a liquid tester.  Both ways are a simple and precise way to monitor our pool’s phosphate level.  Another easy way is to simply take a sample of pool water to your local pool store for analysis.  They can easily test for phosphates in our pool water and we'll have the results immediately.   

How Do I Get Rid Of Phosphates In My Pool?

Phosphates are an inorganic material that's in our pool.  That's a fact.  However, they're a physical object, and no chemical that we add to our pools will "get rid of them".  No chemical will stand all the little phosphates in single file and march them out of our pool.  Now THAT"S getting rid of them.  Phosphate removers typically contain salts of aluminum or lanthanum.  When we add a phosphate remover to our pool water, a chemical reaction takes place which produces insoluble phosphate compounds.  These compounds are caught in the filter and backwashed out.

So, in effect, we really don't need to worry about the phosphate level in our pools.  If we maintain our pool chemistry, there's really no need for a phosphate remover.  You can control phosphate levels by keeping the pool clean and removing debris and other organic matter from your pool when needed.

When Should I Use A Phosphate Remover?

At any point during my pool ownership should I use a phosphate remover?  Absolutely.  Phosphate removers can be an invaluable chemical for certain applications such as:

  • After a heavy rain when large amounts of debris fall into your pool.
  • Fertilizer is accidentely dumped into your pool.
  • Other extreme circumstances such as vandalism.

Do I Need To Use A Phosphate Remover?

During your normal weekly pool maintenance, phosphate removers are simply not needed.  We should focus on keeping our pools clean, our chemicals balanced, and our filter perfectly working.  That's where perfect water comes from.  And that's what we ultimately want.   

Pool Phosphate FAQ 

The list below answers the most common questions of pool phosphates and phosphate removers. 

Does chlorine kill phosphates?

No.  Effective chlorine kills algae and bacteria.  It does not kill phosphates. 

Do phosphates eat up chlorine?

No.  Phosphates are a food source for algae.  Lower chlorine levels are not attributed to higher phosphate levels.  

Do high phosphates cause algae?

No.  Algae in pools is not attributed to higher phosphates levels.  Algae that's present in your pool can be caused by a variety of issues such as low chlorine level, high pH, unbalanced CYA, chlorine demand, and many other factors that have nothing to do with phosphate levels.  

Will phosphate removers make my pool cloudy?  

Yes, an overdose of phosphate removers can cloud up your pool, but it will go away over time.  You can also drain and refill some of your pool water to speed the process along.  There's no chemical to offset an overdose of phosphate remover.