Question about Ideal CYA level


Well-known member
Dec 12, 2018
Taylor K2006 test kit;

My CYA has consistently been between 30-35 (I call it 32 - my wife loses the black dot closer to 35).

Anything wrong with keeping my CYA around 30 so I don’t have to use as much bleach? Benefits to having higher CYA?
As I understand it, the higher my CYA the more bleach I will need, correct?

My numbers from last night:

FC 2.8
CYA 32
PH 7.8
TA 110

21000 gal in ground, vinyl liner.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Your CYA is 40. You can’t eyeball values in between the lines since the scale is logarithmic, not linear. We always round up since CYA is used to set FC targets. You would rather be high on FC then low. Nothing bad happens with slightly high FC. Bad things can happen with low FC.

CYA of 30-40 is fine for a liquid chlorine pool. CYA testing is not that precise.
  • Like
Reactions: dcjbhm


Gold Supporter
Jun 28, 2017
Fresno, CA
Your daily free chlorine loss is the same all things being equal. Yes your FC ideal ppm range is higher as CYA ppm increases but the amount you need to add each day will be the same.
The goal is to minimize your daily chlorine loss by using CYA, always keeping your FC in the zone relative to your CYA ppm and keeping your pool clean. If your FC is much above your ideal CYA/FC range then your chlorine loss per day will be higher. You also may find your FC loss due to sunlight is minimized by a slightly higher CYA level depending on the amount of solar radiation your pool experiences. Every pool system is unique and this is the beauty of self testing, you have the ability to "dial in" your system.