Phosphates in Pool Water:
https://blog.orendatech.com/phosphate...

Where do phosphates come from? How do they get in our swimming pools?
Phosphates are primarily introduced three ways.
1) Chemically phosphoric or phosphonic acidbased products like metal sequestering agents are commonly added to water
2. Organically naturally phosphates come from soils, leaves, rainwater and even people sweating
3. Tap water yes, many drinking water facilities introduce phosphatebased sequestering agents to protect their infrastructure. It's good for the pipes and harmless to people...but creates a problem for our swimming pools.

What are Phosphates?
Phosphates are forms phosphorus found in nature. In our case, there are several types of phosphates that wind up in swimming pools (https://blog.orendatech.com/different.... When compared to other topics in pools, there is surprisingly little scientific detail about phosphates available online. According to the Water Research Center:

“Phosphates exist in three forms: orthophosphate, metaphosphate (or polyphosphate) and organically bound phosphate. Each compound contains phosphorous in a different chemical arrangement. These forms of phosphate occur in living and decaying plant and animal remains, as free ions or weakly chemically bounded in aqueous systems, chemically bonded to sediments and soils, or as mineralized compounds in soil, rocks, and sediments.”

Translation: phosphates are found in soil, which is a combination of broken down rocks (with phosphorus in them), and decaying plant and animal remains. They are prevalent in fertilizers, as well as other pool chemicals (such as metal sequests, which are actually phosphate based).

Algae in Pools
Phosphates are a key micronutrient for algae, but removing phosphates will not necessarily kill algae. Phosphate removal simply limits algae's reproductive rate, allowing chlorine (or your primary sanitizer) to keep up with the growth rate. Removing phosphates can help chlorine prevent algae in pools, but will not directly kill algae. https://blog.orendatech.com/phosphate...

Since phosphates are natural in the ecosystem, they will inevitably get into your pool water in many ways other than tap water: rain water/ground runoff, leaves in the pool, etc. For outdoor pools, these sources are unavoidable.

Eutrophication
In natural water systems like ponds and lakes, algae can take over when there is an overabundance of phosphates. Giant algae blooms can block sunlight, which can starve out other species, and it can be a big problem. Fortunately in swimming pools, we have primary sanitizers to kill algae and keep water clean. https://blog.orendatech.com/algaeno...

Learn more about Phosphates:
Orenda's Third Pillar of Proactive Pool Care: Phosphate Removal:
https://blog.orendatech.com/phosphate...

Consider removing phosphates with PR10,000 by Orenda.