Tons of rain, odd test results

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
So in SoCal we have been having a lot of rain. Tested pool today, FC is fine but I am getting low salt on my aqualink at 2200 ppm. Ph is 7.8, but the TA dropped to 40ppm. CH dropped to 425ppm from 600+ I assume from the rain. So my CSi is fine with TA @40 and ph @7.8 but is my TA too low? I was going to add some baking soda to raise it but thought I would check here first. My TA usually stays around 70-80ppm.
 

JamesW

TFP Expert
Mar 2, 2011
17,374
Brush the pool and let the pump run extra time and recheck everything tomorrow before you do anything.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
12,960
Northern NJ
With low TA and high pH chances are the chemistry will adjust and balance itself.

The time to think about adjusting TA up is when pH is low - 7.0 or below.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,223
Tucson, AZ
The salt reading is likely low due to rainwater mixing with pool water on the surface and fooling the internal conductivity meter in the SWG. You really can’t rely on the SWGs internal “salinity” meter as it really isn’t measuring salt, but rather the conductivity of the water. You can be off by as much as 500ppm or more from the true salt level. Salinity is best measured using a K-1766 salt test kit. It measures actual chloride (Cl-) content and has no interferences so it is a very accurate measure of salt levels.
 

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
Pool temp is about 54-56F. I have a K1766 kit, I will check it out, the SWC is about 100ppm off from the k1766.

Thanks, I will leave things alone and recheck in a couple days.