Scale inhibitor?


Bronze Supporter
Jul 3, 2015
Marietta, Ga
Am I correct that TFP DOES not recommend adding scale inhibitor monthly, unless your water has VERY HIGH calcium levels? Thank You!
FC. 6
CC. 0
PH 7.6
TA 85
CH 140
CYA 50


TFP Expert
Platinum Supporter
May 23, 2015
Tucson, AZ
You have a vinyl pool and your water's CSI (assuming 3400ppm salt and 75F) is -0.56. There is no danger of calcium scale developing at all in your pool. There is a trend among GA pool owners to have issues with iron in their water (either from municipal supplies or blown in from iron-rich Georgia soil) so a scale inhibitor would help to keep iron staining to a minimum. However, if you have never had any problems with iron in your water then there's also no need to use a scale inhibitor.


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
I certainly would not add anything with those good numbers. In fact, your CH should probably come up a little to about 250. It will probably do so on it's own or you can hurry it along by adding some. Keep your pH where it is and you should never have a scale issue.


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
That is not to say though that calcium scale can't develop in a vinyl pool with elevated CSI. No, we do not recommend using a scale inhibitor to avoid scale, we recommend keeping your water balance to avoid scale. More here, Pool School - Calcium Scaling