dclynds

Well-known member
Apr 29, 2016
79
Houston, TX
Pool Size
17500
Surface
Plaster
Chlorine
Liquid Chlorine
Hello TFPers,

Can someone help me outright or point me to a guide on which Sequestering agent to use for which metal problem with respect to pool finish? I need to do an ascorbic acid treatment to get rid of some pale-brownish stains that are cropping up in my pool (confirmed not algae) and I don't know which sequestering agent to purchase or how much to purchase.

My pool is 17,500 gallons, plaster, and I'm pretty sure the stains are iron stains induced by the rock waterfall.

Thanks for your help!
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
18,364
Tucson, AZ
Pool Size
16000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Use either Jack’s Magic products OR Metal Magic. Both of those contain high quality sequestering agents.
 

dclynds

Well-known member
Apr 29, 2016
79
Houston, TX
Pool Size
17500
Surface
Plaster
Chlorine
Liquid Chlorine
Use either Jack’s Magic products OR Metal Magic. Both of those contain high quality sequestering agents.
1.) There are several Jack's Magic...which one should I use?
2.) How much do I need for 17,500 gallons?
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
18,364
Tucson, AZ
Pool Size
16000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
If you read the product descriptions, they tell you what metal they sequester for. Pick the one for iron. The online instructions also have the dosing requirements. There’s typically a high initial dose and then an ongoing maintenance dose until you can get the chlorine levels back up to normal. Doses are typically measured in fluid ounces per 10,000 gallons of pool water. Just note that when you use sequestering agents, it’s not a one time deal. You have to maintain their use or else the staining can return.