If your pool water is green and cloudy, it is possible that the phosphate levels in your pool are too high. Having too many phosphates in your pool can make algae growth more likely and makes it more difficult to maintain proper pool chemistry. Read on to learn more about phosphates, why maintaining low phosphate levels are important, and how to lower the phosphate levels in your pool.

What are Phosphates in a Pool?

Phosphates are organic materials that naturally occur in your pool, coming from dead leaves, lawn fertilizer, and many other sources. At high enough levels, phosphates feed algae to grow in your pool. This will turn your pool’s water green and cloudy.

It is unlikely that you will be able to remove all the phosphates from your pool. However, your goal is to keep phosphate levels low enough that they won’t help algae grow.

Did You Know?

Phosphates are a food source for algae and other aquatic plants. This is why high phosphate levels are one of the factors for having algae in your pool. However, some phosphate in your pool isn’t necessarily going to cause algae growth. Research shows that you need 1,000 parts per billion of phosphate in your pool to really support algae growth.

Dangers of Too High Phosphate Levels

High phosphate levels may affect your health if it is too high. More importantly, it will affect how you manage your pool. High phosphate levels feed algae and promote algae growth, which in turn makes it more difficult and expensive to kill the algae and keep your pool chemistry balanced. High phosphate levels also use up chlorine quickly, making it even more difficult to kill the algae and keep your pool clean.

How to Remove Phosphates in a Pool

In most cases, you won’t need to address phosphates for a very long time. However, there are several things that you can do to prevent phosphates from building up or to remove them. Keeping organic materials, such as leaves and yard waste, out of your pool prevents phosphate buildup. As organic material breaks down, it releases phosphates into the water. Another option is to prevent algae buildup as much as possible.

If you need to remove phosphates, there are chemicals that you can use. Phosphate removers should be used sparingly if at all since they pose a health risk. Always consult a professional before considering phosphate removal chemicals.

FAQs: Phosphates

Can you swim in a pool with high phosphates?

You can swim in a pool that has phosphates in it. In fact, you likely already have. It is important to track the level of phosphates, as extremely high amounts (in the order of 1,000 ppb) can affect your health.

Are phosphates bad for your pool?

Phosphates may not directly harm your pool, but they can indirectly create problems. High levels of phosphates promote algae growth, which can hurt the lining of your pool. Those same phosphates also use up chlorine quickly, making it harder to maintain your pool. This makes your pool maintenance more expensive and time-consuming.

Pro Tip: Most pool test kits, including the test strips, do not test for phosphates. You can purchase a separate phosphate test kit at very little cost.

How do I test pool phosphate levels?

To test pool phosphate levels, you can buy a phosphate testing kit or take a pool water sample to your local pool supply store. Since phosphates take a long time to build up, having the store technicians test your water every time that you go to the store is an easy way to monitor your phosphate levels.

Where do pool phosphates come from?

The phosphates in your pool come from garden fertilizer runoff, rotting leaves, certain pool chemicals, and your city’s water supply. As you swim in your pool, the residue from skin and hair products may also contain phosphates.