Phosphates and nitrates in pool water has become a more common issue than in the past and can wreak havoc with your pool water chemistry if not addressed. Their presence in your pool can increase algae growth, as algae feeds of phosphates. The inability to keep your chlorine levels at a safe sanitising level of between 2-4 ppm, can be a sign there may be a phosphate issue. Some pool companies do not test for phosphates; however an alarm should go off if you have been trying to get your chlorine level to register and no matter how much chlorine and shock you add, the pool still shows no chlorine; a clue that maybe phosphates may be the culprit.
How do phosphates get in the pool in the first place? Phosphates can actually appear from decaying plants, fertiliser, and mineral/metal treatment chemicals, contaminated well water, acid rain, soil runoff, etc. can drop phosphates into your water. Even bird droppings (nitrates as well and believe it or not, human sweat and urine can contribute.
When phosphates are present you will have difficulty controlling algae because your chlorine levels will be used exorbitantly. You can treat the pool water when high levels of phosphates are discovered with various Phosphate removal chemicals, however, these are not cheap and once you are in a higher concentration over 1500-2500 ppm. where you will need quite a bit of phosphate removal chemicals, we then option to a floc treatment. This is a extras cost of water needed to replace the vac to waste and more chemicals to balance the pool.
We test on each visit to help keep Phosphates under control, and having your pool looking better.
The Pool Man