Hayward SWG: instant salt vs average salt vs drop test results

[convan23]

Are these numbers within error tolerance ranges, or should I do something?

Taylor drop test consistently measures at 3200ppm

SWG instant salt reading consistently reads in the 3500s

SWG average salt reading consistently reads in the 3700s.

I find it strange the instant salt reading is always lower then the average. I’ve never seen the instant close to the average, not higher. Always 200-300ppm lower then average.

Salt cell is ~5-6 months old, pool has had salt for ~2-3 months (new pool). It’s been a little low on salt - 2600ppm or so until 8 days ago when I finally got the PB back out to top the salt off since originally not adding enough salt.

I think I read somewhere that you can recalibrate the SWG on the OmniLogic panel, and I was also told at some point that Hayward can come out and calibrate if the SWG reading is off, and sometimes that happens. Are my numbers close enough not to worrry about it, or should I hit up the PB?

 

[Newdude]

I believe @mas985 answered your question a little while ago in posts #41 and 44

Switch to SWG?

All the Hayward systems, determines the salt level from, amps, volts and water temperature. Each of which influences conductivity as well as the salt level. Some SWGs are worse than others at calculating salt levels probably because of calibration issues and variable internal resistance which...

www.troublefreepool.com

 

[convan23]

Thanks for the find @Newdude!

So if average is reading 3700-3800ppm on the SwG and a Taylor drop test is coming in 3000-3200, is that enough difference to warrant talking to Hayward/PB or live with it? It seems to be working fine…

Also, I noticed in that thread commentary about turning SWG off when adding salt and leaving it off for a while before turning it on. Both times the PB came out to add salt that procedure was not followed. When additional salt was added the SWG was on and pump running. When salt was first added the SWG was turned on pretty quickly after (within minutes). What kind of problems could that cause?

Last question: SWG has only been running for 2 months…but has had water flowing through it since November when pool was filled. Should I be thinking about cleaning/inspection the cell soon (every 6 months, starting from fill time) or wait a few more months?

 

[revitup]

“Also, I noticed in that thread commentary about turning SWG off when adding salt and leaving it off for a while before turning it on. Both times the PB came out to add salt that procedure was not followed. When additional salt was added the SWG was on and pump running. When salt was first added the SWG was turned on pretty quickly after (within minutes). What kind of problems could that cause?”
The ‘tech’ that set my FG pool up for the PB did that after build completion. Dumped in way too much salt (I ended up having to drain 50%) and turned on the SCG immediately. The cell failed immediately in the way you are describing and had to be replaced.

 

[Newdude]

+1. You worry about a 'slug' or even just highly concentrated salt water going through the unit. PBs don't know or care and don't want to have to come back tomorrow to turn it back on.

So if average is reading 3700-3800ppm on the SwG and a Taylor drop test is coming in 3000-3200,

3200-3700 is well within 'normal' for the 2 disagreeing. A little but outside of that is no cause for alarm. .......because......

It seems to be working fine…

If the cell is happy, you are happy. Train yourself to use the idiot light. When you are at the low end of the range, you taste it less.

Last question: SWG has only been running for 2 months…but has had water flowing through it since November when pool was filled.

Check it monthly until you are comfortable it's fine to let it go. It takes 2 minutes and I don't care it's 'extra', for something so easy. Once you know your pool isn't susceptible to scaling, go 2 months and the next time 3 and then 4. After that, check beginning, middle and end of the season.

 

[ajw22]

Let’s look at the diagnostics in your SWG…

• Report all readings when you..
  • 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.
• What are the first seven characters of the cell and box serial numbers?

The AquaRite uses the performance of the cell to determine salinity. For each cell (T-3, T-5, T-9 OR T-15), Hayward knows the performance of a properly functioning cell at each temperature and salinity combination. The higher the salinity and/or water temperature, the higher the performance (chlorine output).

To get the performance of the cell, divide the instant salinity by the actual salinity. If the ratio is less than 75%, it's time for a new cell. For example, 2,000 (instant salinity) ÷ 3,600 (measured salinity with a test kit)=56%. Check the cell and clean it if necessary. If that doesn't work, it's time for a new cell.

Hayward Aquarite SWG - Further Reading

www.troublefreepool.com

 

[PoolBrews]

My Hayward T-15 cell is currently showing 3499 instant and 3516 average. My reading from my TFP testkit is 3400. I've been consistently between 100-200 higher on the Hayward than on my readings. You have a difference of 700... not sure if that is an issue, but as long as it's consistent it's most likely OK. A real issue to me would be if I can't keep my salt level at the proper required level without triggering an alarm on my Hayward Omni - i.e. I need to keep it at 3200, my Hayward reads it at 4200 and alarms for too high salt.

With that difference it wouldn't hurt to ask Hayward. I know there is a process to recalibrate a salt cell on an Aqua Rite system, but can't find the same for OmniLogic.

 

[jark87]

My Jandy Aquapure tends to read 10-15% below the Taylor test. I recently had to clean the sensors, as it was reading well below the drop test and was giving me a low salt warning. Once I cleaned the sensors, it was back in the normal range and I understand the variance between the cell readings vs. the drop test. The drop test is what I rely on.

 

[convan23]

Let’s look at the diagnostics in your SWG…

• Report all readings when you..
  • 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.
• What are the first seven characters of the cell and box serial numbers?

@ajw22 thanks, here you go:

I started this morning after the SWG was off all night...probably around 12-13 hours off. I'm taking screenshots of the outdoor controller on my OmniPL as it has a few more readouts then the mobile app.

Here's the readout this morning before turning the SWG on:


After turning the cell on:


After a ~minute with the cell on:


Cell back off:


Turned cell back on:


At this point, it stayed "ON" but not "CHLORINATING" for a solid minute. It started chlorinating:


Here's a photo of the cell and serial number:


Again, it seems to be chlorinating. I don't know how to judge performance... I've had the pump running 24/7 last couple of days and the cell at 30% (15k gal pool) and the chlorine has been creeping up despite sunshine and lots of wind. I had old DPD re-agents and thought the chlorine wasn't really raising, but new DPD test shows CL level at 10+ when I turned it off last night. I don't know if it's chlorinating as much as Pool Math says it should, but that's been hard for me to judge due to lower-then-ideal CYA and lots of sunshine.

I have the pool covered right now, so if there's some other "tests" that I need to do by running the unit and seeing actual chlorine output I can probably do that reliably.

If the cell is happy, you are happy. Train yourself to use the idiot light. When you are at the low end of the range, you taste it less.

Right! I don't want to make a problem out of nothing... But PB is currently responsive and if it "really" fails prematurely in 6 months or more I'd rather them not have reason to put it on me... if it makes sense to get them or Hayward involved sooner I can. I wouldn't have thought anything could be off if it wasn't for this forum

I have never cleaned the cell, it's on my list to do this weekend or sooner as time permits.

 

[mknauss]

I have never cleaned the cell, it's on my list to do this weekend or sooner as time permits.

Inspect it. Do NOT use acid on the cell unless the scale is so much that you can loosen it with a spray of water or a popsicle stick. Acid used on the cell reduces its life by removing the rare earth metals on the plates.

 

[convan23]

@mknauss yeah, I plan on looking up the TFP videos on it before touching it. Haven't done it before though... I imagine the scale will be easy to see if there is any?

 

[mknauss]

I imagine the scale will be easy to see if there is any?

Yes. Though there should be none or very minimal. I have never had to clean my SWCG with acid. It is 8 years old.

 

[convan23]

+1. You worry about a 'slug' or even just highly concentrated salt water going through the unit. PBs don't know or care and don't want to have to come back tomorrow to turn it back on.

If this happened would it be obvious or have visible damage when I inspect the unit?

 

[Newdude]

Again, it seems to be chlorinating. I don't know how to judge performance...

You either produce a reasonable amount of FC per runtime per the unit you have, or you don't. Anything close will seem OK, and will be OK.

You can drive yourself nuts knowing too much here. My IC60 with no automation had a green light for producing and thats it. I went 6+ years with that light alone before landing here. The idiot light and the idiot were just the bestest of friends. Helllllllllllo little green light !!! So nice to see you, catch you next week.

If I was you, I'd calibrate it now, for learning sake. It's good to know and then you'll know. You'll also know if it goes right back to screwy in a short while, that you can disregard it if it remains that much off. If it ever goes considerably further from actual, then you know how to calibrate it.

I imagine the scale will be easy to see if there is any?

You have dull metal plates thay are silver-y but not shiny. You are looking for a toothpaste like build up. Even if its only a little, you will know whatever amount of toothpaste doesn't belong there.

If this happened would it be obvious or have visible damage when I inspect the unit

@mknauss can confirm/deny but I'm pretty sure the cell appears healthy and just stops producing like it reached end of life.

 

[mknauss]

High salt in an Aquarite system typically damages the control board before the cell. Read the Wiki that Allen linked to earlier.

 

[ajw22]

Your cell diagnostics look fine. Your cell current is in the low 6 amps. Max cell current is 8 amps and if it hits 8 amps it will shutdown. Cell current is proportional to the salinity reading.

You don't want to let your salt level get high with Hayward cells as high salt levels cause high amps which cause heat in the board which cause failures on the board.

That is why you want to turn off the SWG when adding salt. Especially with Hayward cells. if it sees a slug of high salt water it will ramp up the amps which can damage the board. Give the salt at least 24 hours to dissolve and evenly distribute in the water before you turn on the SWG after adding salt.

And don't give the cell unnecessary acid washes.

 

[convan23]

If after about 3-5 minutes of running the instant drops to this photo, is that a concern for a cell that’s only 6 months old?

 

[ajw22]

If after about 3-5 minutes of running the instant drops to this photo, is that a concern for a cell that’s only 6 months old?

No. Both those numbers are calculated, not measured.

To get the performance of the cell, divide the instant salinity by the actual salinity. If the ratio is less than 75%, it's time for a new cell. For example, 2,000 (instant salinity) ÷ 3,600 (measured salinity with a test kit)=56%. Check the cell and clean it if necessary. If that doesn't work, it's time for a new cell.

Your Taylor drop test is coming in 3000-3200 and instant at 3200 says your cell is operating at 100%.

Hayward Aquarite SWG - Further Reading

www.troublefreepool.com

 

[convan23]

I misread that copy the first time you posted it, and thought it was the ratio between instant and average not instant and actual. Got it!!

 

[BMerrill]

What the readings mean directly from Hayward.

Inst salt = the cells reading of the current salt PPM
Avg Salt = the average salt reading of the last 3 cycles of the cell.

You can match Instant Salt to the Avg Salt value only in the Chlorinator diagnostic menu at the controller by pressing the the [+/-] button.