| or Call:

Tweet Me!

What you need to know

Swimming Pool Water Chemistry

Chlorine / CYA Chart

Perhaps a cornerstone element of TFPC is understanding the relationship between the chlorine in your pool and the stabilizer you put in to protect the chlorine from the sun. Generally, the more stabilizer, the more chlorine you need to maintain its effectiveness. The charts below show the recommended relationship for outdoor residential pools.

Non -SWG Pools

CYA (Stabilizer) Minimum FC Target FC Shock FC
20*
2
3
10
30
2
4
12
40
3
5
16
50
4
6
20
60
5
7
24
70*
5
8
28
80*
6
9
31
90*
7
10
35
100*
7
12
39

SWG Pools

CYA (Stabilizer) Minimum FC Target FC Shock FC
60*
3
4
24
70
3
5
28
80
4
6
31

* Not recommended

The shock levels shown have equivalent effective disinfecting chlorine amounts. At very high CYA levels it can be impractical to reach such high FC levels. At CYA levels over 80, a partial drain/refill to lower the CYA level is usually required before you start the SLAM/SHOCK process.

Most saltwater chlorine generator (SWG) pools appear to prevent algae at a lower minimum FC level compared with the minimum FC column for manually dosed pools.

For indoor pools we recommend CYA between 20 and 30. The reasoning for using CYA indoors is quite different. For more information please ask