Sequestering agent for IG pool

Jun 2, 2008
I just had our IG pool refinished.The company warranties stains as long as you keep a 10-12 ppm seqestering agent in the water.They suggested to use jacks magic blue stuff.My question is I understand that these sequestering agents add phosphates to the water.My phosphates are pretty high from the source water(about 1000 ppb).If I keep the agent up to the recommendation Im worring about a algae outbreak with so much phosphate in the water and still adding more.What would you suggest I do?Add the agent and monitor phosphates and then add a phosphate remover.I keep the chlorine about 6 with the cya at 50.I tested for nitrates and have 0 nitrates.Thanks


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
You really don't need to worry about the phosphate level. My pool has a phosphate level of well above 4,000 and I don't have problems with it. Very low phosphate levels can help prevent algae, but normal chlorine levels will do that anyway even with phosphates.