Can't figure out salt cell issue

[rmturner54]

I have got plenty of salt in the pool. The cell is clean. It is 3 years old. T3 cell. The cell voltage and current switches polarities ok.
First I started having some really weird behavior and readings not normal. Until I determined first that my salt level was low. So I corrected that issue.
Now I am seeing large differences between the average reading and instant salt reading. I have re-calibrated several times. For instance, this morning it was 3800 avg/2800 inst.
So I performed the calibrate function, which is while in the instant reading move function switch from auto to super chlor and back to auto.
Wait a few seconds and check readings. All was good. 2800 avg/2800 inst. 4hours later I check the reading and I have 3600 avg/4100 inst.
I started noticing this behavior yesterday but did not think much of it till today. I can petty much figure out a lot of things, but this one I am having a problem with.
I did reach out to Hayward tech support.
Thanks for any help that can be provided.

 

[mas985]

First, what you are describing is not really a "calibration", it simply replaces the average salt level with the instantaneous level. Second, during the start of every cycle, the average valve is updated.

If you track instantaneous values in the unit right after the cell is energized, the current/salt level will start at a higher level than what it eventually settles down to. This is due to the conductivity in the cell and circuitry changing with temperature. So my point is that the instantaneous level depends on when you take the measurement in relation to when the cell was energized. So there may be some variability there. If you always wait a few minutes after cell energizing, then the instantaneous level should be stable and usually well below the "average" level since that is determined early in the cell cycle. However, if you check the instantaneous level to soon after energizing, it could be well above the average level because it has not reached stability. So that can be one source of error.

Lastly, if you just added salt, there is a good chance it has not fully dissolved so you may be getting pockets of higher concentrations which may also explain why there are variations in the readings.

Forgot to mention that none of this really matters as long as the SWG is happy and producing chlorine.

 

[rmturner54]

Thanks for the explanation. The salt was added 2 days ago. So looking at my display now which is apprx 40 mins after I posted.
My avg is now 4100, instant 3600. I know the instant value should below below the average and it is now. So maybe the system starting to level out so to speak.
I never taken the readings serious until after the cell has switched polarity and stabilized for many minutes.
I am now just going to keep a close watch.
Thanks again for your reply and details

 

[rmturner54]

After another day of operation I believe my system has stabilized, actually salt readings were 3800 avg/3800 inst.