SWG positive and negative salt readings different

tdaddy2081

Member
Jun 20, 2013
5
Chillicothe ohio
Hey all, I suspect my SWG cell is going bad, I have a t cell 15 with aqua rite control board. The negative diagnostic shows 3100ppm salt and the positive shows 2400ppm. I tested and it is around 3100ppm. Do I have a bad cell or a board issue? The Amps and volt readings are what they should be for each respective salt level but not sure why the difference in salt levels? I added salt and the neagative increased as expected but the positive only increased slightly. Any insight would be appreciated.
 

Ubertenere

New member
Sep 13, 2018
3
Waxhaw, NC
While On the negative setting after the number settles down switch the switch to super chlorinate and back down to auto, this is how you calibrate the sensor, if the negative agrees with your test it is working properly.
 

JamesW

TFP Expert
Mar 2, 2011
16,589
While On the negative setting after the number settles down switch the switch to super chlorinate and back down to auto, this is how you calibrate the sensor, if the negative agrees with your test it is working properly.
The salinity measurement can't be calibrated. Moving the switch from auto to superchlorinate and back to auto only updates the average salinity to match the instant salinity.

If the instant salinity in both polarities is way different, it usually means a scaled cell or the cell is bad.
 

Saturn94

Well-known member
Mar 11, 2015
707
Virginia
The salinity measurement can't be calibrated. Moving the switch from auto to superchlorinate and back to auto only updates the average salinity to match the instant salinity.

If the instant salinity in both polarities is way different, it usually means a scaled cell or the cell is bad.
How much difference between polarities might constitute a bad cell (assuming there’s no scaling)? Is some difference normal?
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,797
Pleasanton, CA
While the cell may be going bad, there is no reason to replace it if it is still generating chlorine. Mine did the same thing at end of life but I kept running it for quite a while. The amount of CL it generates will slowly decrease with time and at some point it won't be able to generate enough CL even at 100% setting to reach target and then you can replace it. In fact I still have the old cell and it still generates CL just not very much. You can compensate with more run time and higher salt levels (up to a point).