logo
    • News
    • Classifieds
    • Free Subscription
    • Book Store
    • Submit
      • Submit a Classified Ad
      • Submit an Educational Announcement
      • Submit a letter to The Editor
    • Past Issues
    • Regional Trade Shows
    • Testimonials
    • Contact
    • News
    • Classifieds
    • Free Subscription
    • Book Store
    • Submit
      • Submit a Classified Ad
      • Submit an Educational Announcement
      • Submit a letter to The Editor
    • Past Issues
    • Regional Trade Shows
    • Testimonials
    • Contact
News
October 31, 2021
Why we need to remove phosphates

If you’ve got a pool with a persistent algae problem that doesn’t seem to respond to a reasonable amount of chlorine, it’s a good idea to test for both cyanuric acid and phosphates.

That’s because cyanuric acid reduces the kill rate of chlorine, while phosphates amplify the growth rate of chlorine.

If the phosphates are high (beyond about 500 ppb can become problematic) a phosphate remover can go a long way in slowing algae growth so that chlorine can work more efficiently.

The APSP’s 2009 National Standards offers the following justification for phosphate removal: Phosphorous is a non-metallic element and an essential nutrient for all living organisms, including bacteria and algae. Phosphate does not create a chlorine demand since the phosphate ion does not react with free chlorine. However, inadequate maintenance and sanitation can allow algae and bacteria to reproduce rapidly and utilize phosphorous as a nutrient. Under these circumstances, the multiplying algae or bacterial populations will cause a chlorine demand. In other words, phosphates are bad for pools and spas because they are a major nutrient for algae. Some pools that have high phosphate concentrations have difficulty controlling algae despite the chlorine.

Phosphates are typically removed from swimming pools with lanthanumbased chemicals. Some examples include lanthanum chloride, lanthanum sulfate, and lanthanum carboxylate. Added to water, an ion exchange reaction takes place. The lanthanide drops its counter ion in preference for the phosphate. Thus, lanthanum phosphate forms, a compound that is insoluble in water, and precipitates out of solution.

Service professionals caring for pools with high phosphate levels should note that when a phosphate remover is used, the water usually appears worse before it gets better. The water becomes cloudy because the product formed, lanthanum phosphate, is insoluble in water. But that is what the chemical is designed to do, and techs can tell homeowners to have patience with the filtration system before things get better.

LATEST NEWS
Homes with pools raise price and sell speed
News
Homes with pools raise price and sell speed
Demand for houses with swimming pools remains strong in warm weather states
June 30, 2025
By Marcelle Dibrell As summer begins to heat up, so does the U.S. housing market — though not evenly across the board. Buyers and sellers are navigati...
this is a test
News
Final summer survey results tallied
June 30, 2025
Each year, Service Industry News takes the pulse of the pool and spa service sector through our comprehensive survey, and in this final installment of...
this is a test
during the pandemic peak. This ….
News
during the pandemic peak. This ….
June 30, 2025
during the pandemic peak. This has resulted in a widening gap between buyers and sellers. According to Redfin, there are approximately 1.9 million sel...
this is a test
News
Chem exposure sends 5 to hospital
June 30, 2025
Several patrons at a residential community swimming pool in Apache Junction, Arizona, were sent to the hospital following a hazardous materials incide...
this is a test
News
New Jersey city pool workers arrested
June 30, 2025
A group of municipal pool workers in New Jersey has been arrested for allegedly stealing chemicals from the Secaucus town pool to support their privat...
this is a test
Gators swim to escape heat wave
News
Gators swim to escape heat wave
June 30, 2025
As summer heats up across the South, pool technicians are being reminded that it’s not just algae or cloudy water that can cause a service delay. Some...
this is a test
Read Our Newsletter
ePaper
coogle_play
app_store
Free Subscription
View Current Print Ads
Educational Announcements
Aquatic Training Institute

Educational Leverage

Foundation For Pool Industry Education

Locey Pool

Pool Chemistry Training Institute

Pool & Hot Tub Alliance

Portofino University

Underwater Pool Masters
Trade Show Dates
  • The International Pool Spa Patio Expo
    Nov. 12-14, Dallas, Texas
  • The Pool and Spa Show
    Jan. 28-30, Atlantic City, New Jersey
  • 35th Annual National Plasterers Conference
    Feb. 26-28, Lake Buena Vista, Florida
  • The Southwest Pool and Spa Show
    Feb. 4-8, Houston, Texas
  • The Western Pool and Spa Show
    Feb. 6-8, Long Beach, California
Books to Order
About Us Terms of Use Privacy Policy
We use cookies to ensure that our website gives you the best experience possible. By continuing to use this website, you agree to this use of cookies.OK