A couple of suggestions based on my introduction to the site


Well-known member
May 14, 2012
• StainFree or Citric acid will cause high demand of chlorine, maybe upwards of 12 gallons.
• Shouldn’t CYA above 0 be the first step even before adding chlorine?
• Why not go overkill with adding chlorine? What are the effects of having too high of a chlorine level. Seem like in the beginning of my process that the stain free and the algae were just eating up the chlorine and it would have made sense to have more than not enough.
• It should be noted that high FC will effect PH reading. Not sure I saw that anywhere except when someone posted it.
• Did not see a local copy of the poolcalculator
• Maybe a note should be made when testing FC that the water might not turn pink with a low FC number. I thought I was doing something wrong when testing and not seeing the water change color. What it really was was that there was still little or no free chlorine.
• Chlorine / CYA Chart is confusing if your CYA is at 0. Maybe it would make sense to add a note that if your CYA is at zero then set a target for a CYA of 30 to 40. CYA target of 30-40 according the below mentioned chart results in a Shock FC of 12-16. Enter this value into the poolcalculator with all other relevant information to calculate amount of chlorine to be added to achieve these levels.
• Modify the following statement by adding what is in quotes.
1. Add enough chlorine to bring FC up to shock level (or a little higher) “Shock level is according the Chlorine/CYA chart”
• Modify the following statement by adding what is in quotes.
Depending on what kind of filter you have, it can take the filter a week or more to completely clear up the water, even after all of the algae is dead. “It could also take very large amounts of chlorine” DE filters are usually much faster than that, but require frequent attention when cleaning up algae. Sand filters are the slowest, and cartridge filters are somewhere in-between.
• Need to add somewhere that you enter the Shock FC value into the pool calculator to determine how much chlorine to add.


LifeTime Supporter
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TFP Expert
May 7, 2007
Silver Spring, MD
Re: A couple of suggestions based on my introduction to the

PH is first, then chlorine, and only then CYA.

Extremely high FC levels can cause damage, especially to vinyl liners and pool heaters. Extremely high FC levels can also cause metal stains, if there are metals in the water.