Phosphates are compounds of the element phosphorous that add nutrients to pool water that promote algae growth. Phosphates also combine with calcium and form calcium phosphate which not all filters can filter out. In high amounts, the calcium phosphate causes cloudy water leaving your pool looking not so inviting.

No one wants to be bummed out missing any swim time, so let's take a look at phosphate sources:

- Plant & Lawn Fertilizers: while you aren't putting these items directly into your pool water, consider any sprinkler or rain water run off that enters the pool

- Decomposing Plants: your filter basket, skimmer baskets, cleaner debris bag, all hold leaves, grass clippings, and other plant life that can decompose over time. regular pool maintenance is necessary to minimize their impact on the pool water, this includes skimming and vacuuming any leaves and other debris from your pool surface and floor as well as emptying those baskets.

- Skin Care Products: when bathers enter the pool, they tend to be wearing sun screen, bug spray, make up, lotions, and other products,  all which can add to the pool's phosphate levels

- Water Source: whether filling the pool from a well or municipal water, it contains phosphates

- Pool Chemicals: keep an eye on the ingredients in the pool chemicals used in the pool and spa, some may contain phosphates and be adding to the issue more than realized

It is important to be proactive with testing the phosphate levels of the pool and spa before they become an issue, especially because some sources cannot be avoided. Testing can be easy as a test strip dipped into a sample of water giving a result in about 10 seconds.

Keep in mind, if using a phosphate remover product, while it does lower phosphate levels, it does not actually kill the existing algae. Once algae has bloomed, only shock or algaecide will kill the algae and be sure to brush the algae to remove the hard outer shell of the algae blossoms to allow the shock and algaecide to work more efficiently.


As with all pool and spa chemicals be sure to fully read the instructions and follow safe handling and storage procedures.

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