Different CSI readings

[Dave224]

First of all my latest test results with the Taylor K-2006:
FC 5.0
CC 0
PH 7.5
TA 80
CH 130
CYA 60
Temp 87 f.
When I plug those numbers into Pool Math, it gives me a CSI of -0.63. When I use the Taylor whiz wheel, it gives me a CSI of -.30. I am confused about the difference. I am considering bumping the CH up to 200, as this will produce a CSI of about -.13 according to the whiz wheel, anyway. Ideas?

 

[JamesW]

The Watergram requires that you use the “Adjusted TA”.

The adjusted alkalinity is the TA - (CYA x cf).

Cf is the correction factor, which is based on the pH.

pH........CF
7.0.......0.22
7.1.......0.24
7.2.......0.26
7.3.......0.28
7.4.......0.30
7.5.......0.32
7.6.......0.33
7.7.......0.34
7.8.......0.35
7.9.......0.36

For example, if the pH = 7.6, TA = 90 and CYA = 70, the adjusted alkalinity is 90 - (70 x 0.33) = 67.

In any case, it’s a lot easier to use the PoolMath app or page.

PoolMath

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www.troublefreepool.com

What are the readings for CYA and salt?

 

[JamesW]

The book that comes with the Taylor kit does mention the adjusted TA.

 

[Dave224]

Salt is 3000. I guess I forgot to include that. That makes the CSI more negative too, I think. And the TA is lower than I thought. Thanks for the info.