Phoslock in Depth

Before, during, and after a Phoslock application. 

Phoslock is a patented phosphorus locking technology to restore water quality in ponds, lakes and reservoirs.  Phoslock was developed by the Australian national science agency, Commonwealth Scientific and Industrial Research Organization (CSIRO), to remove phosphorus from water bodies and restore water quality. For over ten years, Phoslock has been successfully used in water resource restoration programs around the world.  Although Phoslock is a new technology to the United States (2010), it is rapidly emerging as the most effective phosphorus inactivation and water quality restoration solution for ponds, lakes and reservoirs.

Given the favorable features of Phoslock, such as its very low toxicity, its ability to permanently bind free reactive phosphorus (FRP) over a wide range of water chemistries, and the fact that it does not form flocs, Phoslock is emerging as the most effective phosphorus locking technology for in-situ phosphorus management in surface water.


Case Studies

Water Quality Restoration of a Phosphorus Impaired Florida Lake

Similar to many other lakes in Florida and around the United States, Pine Lake has been plagued by eutrophication caused by excessive phosphorus accumulation.  Listed as phosphorus impaired by the Florida Department of Environmental Protection, Pine Lake required mitigation restore water quality. 

Water Quality Restoration in Laguna Niguel Lake

Phoslock provided the water resource managers and public who enjoy Laguna Niguel Lake an ecologically sound in-situ solution to address phosphorus pollution and restore water quality.

Lake Lorene

AquaTechnex, LLC biologists along with Twin Lake HOA concluded the excess phosphorus concentrations in Lake Lorene needed to be reduced in order to improve water quality.  The recommended in‐situ approach for Lake Lorene was the application of the phosphorus locking technology Phoslock (applied June 2012). Monitoring was conducted throughout the season resulting in a 53% reduction in free reactive phosphorus(FRP), a 40% reduction in total phosphorus 4 months after application.  The reduction of in water phosphorus concentrations in Lake Lorene demonstrated the ability of Phoslock initially inactivate FRP in the water column, immediately bind available phosphorus in the sediments and break the cycling of phosphorus in the lake.

 Crooked Stick Golf Club (2011) 

SePRO Corporation, in partnership with Crooked Stick Golf Club, Indiana, initiated a phosphorus mitigation program with Phoslock on June 23, 2011. The objective of the project was to reduce phosphorus levels and restore water quality in this pond. Total phosphorus level were measured at 182 ppb prior to application, dropped 58% to 76 ppb within 48 hours following application and two months later remained at levels 70% lower than pre-applications conditions. 

1st U.S. Phoslock Application, California (2010) 

Mason Lake, California had chronic water quality issues impacting the health and enjoyment of the waterbody. The lake management firm AquaTechnex selected the proactive solution of Phoslock to address the high levels of phosphorus (water & sediment) and reset the eutrophication clock of this lake. The Phoslock application resulted in a 45% reduction in total phosphorus one month after application, a reduction of ortho-phosphorus below limits of detection for 4 months following application and improved water clarity by 4 feet. This first operational application in the United States confirmed the international successes of Phoslock programs and demonstrated the impressive ability of this patented technology to bind phosphorus and restore water quality.

Het Groene Eiland, Netherlands(2009)

The lake at the “Het Groene Eiland” camping park near the town of Appeltern in the Netherlands.  The aim of the Phoslock application was to remove 110 kg and 31 kg of phosphorus from the available nutrient pool of both the water column and the releasable fraction of the sediment for the entire lake.  The lake was treated with Phoslock on the 16th and 17th of April 2008.   A planned low does second application was applied on the 31st of March 2009 to bind phosphorus unaccounted for in the first application.   The application of Phoslock® to “Het Groene Eiland” has reduced the overall phosphorus levels and restore water quality.  The lake has remained open for recreational use without interruption since the application of Phoslock.


Phoslock is not an algaecide. If an algae bloom is present, treat with a SePRO algaecide prior to a Phoslock application. Phoslock is a registered trademark of Phoslock Water Solutions Ltd.