At what point do you need to add sequestrant, say for iron? Do you wait for the stains to appear or is this a preventative measure? I ask because when I do my ch test my test solution turns purple not blue. I read that when the sample turns purple it is a sign you have metals...iron in the water.
I am tempted to take the pool water in to be tested for iron but from reading here the pool store testing is not always accurate.
Any suggestions and what is the best sequestrant to buy?
Also, my pool was filled in the fall of 09 with municipal water but I have a well I use for topping off the pool and I know there is iron present in the well water.
Thanks for any suggestions!