Low salt readings on multiple brand new salt cells

IamMark

Member
Sep 1, 2012
7
I have an Aquarite chlorine generator that's probably around 20 years old but had its board replaced within the last 5 years. My Hayward T-CELL-15 started failing after only 2.5 years. Due to the significant increase in prices and low availability on Hayward's salt cells, I decided to give the salt cells sold by Salt Solutions Inc a try. These are essentially remanufactured Hayward cells. Long story short, I am now on my 3rd replacement salt cell from this company. After resetting the salt readings, they initially show a salt level of 3,000 ppm. However, after running for several hours, the instant salt readings drop down to around 2,400 - 2,500 ppm. This is causing the average salt level to read around 2,800 - 2,900 ppm. I had my salt level tested at the pool store, and they said it was 3,400. I bought new salt strips and tried a couple of them, and they read a little above 3,200.

Any ideas why the instant salt reading would be so low after running for several hours? My concern is that if this is happening on brand new cells, it will potentially start reading lower as time goes on and eventually stop generating chlorine. Should I be concerned?
 

IamMark

Member
Sep 1, 2012
7
I actually reviewed the Wiki several weeks back when I first had this problem. Is there something in particular that I should be paying attention to? The person from Salt Solutions Inc went over the numbers from my Aquarite to see if it was functioning properly, and he said they seemed within specs.

Again, the main problem I'm seeing is that the instant salt reading starts off normal (2,900 - 3,000 ppm), but over the course of the day, it drops down to 2,400. As far as I could see, the Wiki doesn't really address this scenario.
 

ajw22

Gold Supporter
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Jul 21, 2013
28,557
Northern NJ
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Salt Water Generator
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Pentair Intellichlor IC-60
I suspect you have some components or solder joints beginning to fail on your 5 year old board. The Hayward boards have known problems of failing from overheating. As components overheat their tolerances drift which can cause the salinity readings drop over time.

I would pull the board and examine the components closely for any signs of brittleness or overheating.

Was that replacement board an original Hayward part or a 3rd party clone?

@JamesW
 

JamesW

TFP Expert
Mar 2, 2011
27,715
For AquaRite, move the switch from auto to off and check all of the readings.

Move the switch back to auto and recheck the readings.

Move the switch to off for a minute and then back to auto and recheck the readings.

Switching the unit off and then back on makes the unit reverse polarity.

Report all readings.

What are the first seven characters of the cell and box serial numbers?

What is the actual salinity and how are you measuring it?

What is the T-cell size?

Is the T-cell size set correctly in settings?

To get the performance percentage of the cell in each polarity, divide the instant salinity reading in each polarity by the actual salinity reading.

For example, if the instant reading is 3,300 ppm and the actual salinity reading is 3,300 ppm, then the salt cell is working at 100%.

However, if the actual salinity was 3,800 ppm, then the performance percentage is 86.8%.

Anything over 75% is acceptable.

At75%, or lower, in either polarity, it's time to consider replacing the cell.

The instant salinity in both polarities should be about the same (+/- about 200 ppm).

You need to be really sure about the actual salinity reading.

You need to use a K-1766 salt test kit or a calibrated meter.

K-1766 Taylor Salt Test

Note that ProLogic, AquaLogic and AquaPlus use the Hayward T Cell.

However, the procedure to get the diagnostic readings is different.

Here is the procedure for ProLogic, AquaLogic and AquaPlus:

Go to the diagnostic screen, note the readings and then press the + button to reverse the polarity.

When the new numbers appear, see what they are.

Then, press + again and note the new readings.
 

JamesW

TFP Expert
Mar 2, 2011
27,715
What is the flow rate?

Try putting the hump down.

Do you have pictures of everything?
 

IamMark

Member
Sep 1, 2012
7
I suspect you have some components or solder joints beginning to fail on your 5 year old board. The Hayward boards have known problems of failing from overheating. As components overheat their tolerances drift which can cause the salinity readings drop over time.

I would pull the board and examine the components closely for any signs of brittleness or overheating.

Was that replacement board an original Hayward part or a 3rd party clone?

@JamesW
Ok, that's good to know. I'm definitely not an electrician, but I imagine it should be pretty obvious if components are going bad. Does the board need to be removed to see the components, or is taking the panels of the Aquarite be enough?

I'm pretty sure it was a Hayward original, but I'm not positive.
 

IamMark

Member
Sep 1, 2012
7
For AquaRite, move the switch from auto to off and check all of the readings.
Default salt display: 3000
Pool temp: 85
Cell Voltage: 32.8
Cell current: 0
Desired output (% of the knob): 100
Instant salinity: 0
Product name: al-0
Software revision (r.XX): r 1.58
Cell type: t-15
Move the switch back to auto and recheck the readings.
Default salt display: 3000
Pool temp: 85
Cell Voltage: 24.6
Cell current: 5.75
Desired output (% of the knob): 100
Instant salinity: -3000
Move the switch to off for a minute and then back to auto and recheck the readings.
Default salt display: 3000
Pool temp: 85
Cell Voltage: 24.7
Cell current: 5.84
Desired output (% of the knob): 100
Instant salinity: -3000
Switching the unit off and then back on makes the unit reverse polarity.

Report all readings.

What are the first seven characters of the cell and box serial numbers?
This isn't a genuine Hayward cell. Its from Salt Solutions Inc, so I don't this is relevant. They are brand new.
What is the actual salinity and how are you measuring it?
Salinity as test by my local pool store: 3,400 ppm. Brand new salt strips: 3,200
What is the T-cell size?
T-CELL-15
Is the T-cell size set correctly in settings?
Yes
To get the performance percentage of the cell in each polarity, divide the instant salinity reading in each polarity by the actual salinity reading.

For example, if the instant reading is 3,300 ppm and the actual salinity reading is 3,300 ppm, then the salt cell is working at 100%.

However, if the actual salinity was 3,800 ppm, then the performance percentage is 86.8%.

Anything over 75% is acceptable.

At75%, or lower, in either polarity, it's time to consider replacing the cell.
When it gets to its lowest (2,400 ppm), it is definitely below 75%
The instant salinity in both polarities should be about the same (+/- about 200 ppm).

You need to be really sure about the actual salinity reading.

You need to use a K-1766 salt test kit or a calibrated meter.

K-1766 Taylor Salt Test
I would agree that using this kit would be ideal. But considering the pool store and the strips are relatively close, and the reading on the Aquarite is off by as much as 1,000 ppm, I don't think it's necessary to use the kit for this purpose.
Note that ProLogic, AquaLogic and AquaPlus use the Hayward T Cell.

However, the procedure to get the diagnostic readings is different.

Here is the procedure for ProLogic, AquaLogic and AquaPlus:

Go to the diagnostic screen, note the readings and then press the + button to reverse the polarity.

When the new numbers appear, see what they are.

Then, press + again and note the new readings.
Hi,

Please see above.
 

JamesW

TFP Expert
Mar 2, 2011
27,715
I think that the box and cell are probably fine.

I would suspect that if the hump is up, and the flow is low, you are getting a buildup of gas in the cell, which can expose a portion of the plates above the water level in the cell.

I would try increasing the flow rate and putting the cell hump sideways or down.

What is the flow rate?

Do you have pictures of everything?
 

JamesW

TFP Expert
Mar 2, 2011
27,715
If the problem happens with better flow and the hump down, check all of the diagnostic readings while the salinity reading is low and then do the off/on procedure again.
 

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IamMark

Member
Sep 1, 2012
7
I think that the box and cell are probably fine.

I would suspect that if the hump is up, and the flow is low, you are getting a buildup of gas in the cell, which can expose a portion of the plates above the water level in the cell.

I would try increasing the flow rate and putting the cell hump sideways or down.
Thanks for looking at the numbers. The salt cell is already installed with the hump down. I have no idea what the flow rate is, but its enough to run water through my solar array.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
14,689
Pleasanton, CA
Pool Size
20000
Surface
Plaster
Chlorine
Salt Water Generator
Just curious, does the amperage change with time look something like this?

1628797711859.png

Max and min amps are probably different but I was wondering if yours follows a similar curve. From my own experience, I believe this is indicative of a failing cell.
 

JamesW

TFP Expert
Mar 2, 2011
27,715
If the instant salinity and amperage drop off over time and the voltage and water flow are good, the cell is probably bad.

The genuine Hayward cells are more expensive, but they also have better quality control.

You get what you pay for in this case.
 
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