High Phosphates

[Pool USer]

Why all of a sudden is there a test and concern about High Phospates. In 28 years it was never a problem +4000, but now it is. I Use a normal chlorine floater with water temperature about 92 degrees (heated). Pebble Sheen finsh (1 year old).

[chem geek]

Thanks for your measurement. This is the kind of information I am looking for. Can you tell me your pool's current Cyanuric Acid (CYA) level and Free Chlorine (FC) level? Also, do you use any sort of algaecide (copper ionization or copper sulfate; linear quat or PolyQuat)?

Phosphates are one of several nutrients algae needs to grow -- it's a source of phosphorous. Others include nitrates (or ammonia -- basically a source of nitrogen) and carbonates (a source of carbon).

As you have found out, even in the presence of nutrients (e.g. phosphates), algae will not grow if being killed faster by chlorine. I am currently trying to find out the phosphate level at which our current recommendations for minimum FC levels relative to CYA levels would no longer be enough and to get some sense for that relationship.

I look at phosphate removers as just another option for algae control, just as various algaecides are other options. Chlorine alone can keep away algae, but it needs to be kept up at a high enough level relative to CYA (though some disagree).

Thanks,
Richard

[mr_clean]

when I have seen this problem the phosphate level is close to 1000 and the norm. should be 125-0.

I think your correct on chemicals readings and it should take care of it in most cases.

the pools with 1000 readings all have one thing in common and that is alot of bush/trees in back yard.

the pools with very little plant life have low readings.

when I have explained this to homeowners and they cut back their "jungle" the reading stay down.