Phosphates

If your pool water is struggling to stay clear and turning green and cloudy, it is possible that the phosphate levels in your pool are too high. This is a big problem we struggle with here in SWFL (read on to find out why).  Having too many phosphates in your pool can make algae growth more likely and makes it more difficult to maintain proper pool chemistry.  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, municipal and well water sources and many others. At high enough levels, phosphates feed algae to grow in your pool.  Essentially the phosphates feed algae growth, which rapidly uses up your sanitizer (chlorine, bromine etc.), turning your pool’s water green and cloudy. 

How to Remove Phosphates in a Pool

In SWFL, typically every May/June, we see a big increase in phosphate levels.  Typically one treatment per year during this time is enough to keep the levels down all year.  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 make sure you don’t have any leaks in your pool.  City water can add to a rising phosphate problem. 

If you need to remove phosphates, you can apply a treatment to the pool where-in the chemical additive binds to the phosphates and gets trapped in the pool filter.  This treatment is very effective at lowering your phosphates levels but will clog up the filter pretty badly.  Its important to either wash or replace you filter following this treatment to ensure proper water circulation. 

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 plaster as well as equipment in 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.

How do I test pool phosphate levels?

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 or ask us and we would be happy to check for you.

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 airborne/runoff, rotting leaves, well water, 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.