Salinity testing gives different results

[Russmd]

We've been having various issues with my Jandy 1400 recently, and my pool guy just told me that his digital meter read a salinity of 4800. My Jandy read 4000 but it's calibration had been messed with recently. My Leslie's test strips show around 4600. Leslie's Pool store electronic meter shows 4800. Then I got a Taylor silver nitrate reagent kit and it reads 5800! Reproducible - 28 drops with 10ml sample! I'm not sure what to believe and where to go from here. 5800, really!
Thanks.

 

[JoyfulNoise]

We've been having various issues with my Jandy 1400 recently, and my pool guy just told me that his digital meter read a salinity of 4800. My Jandy read 4000 but it's calibration had been messed with recently. My Leslie's test strips show around 4600. Leslie's Pool store electronic meter shows 4800. Then I got a Taylor silver nitrate reagent kit and it reads 5800! Reproducible - 28 drops with 10ml sample! I'm not sure what to believe and where to go from here. 5800, really!
Thanks.

The drops will be the most accurate from an absolute value perspective. I would believe your water is >5000ppm.

The bigger problem is you said the calibration was messed with. That's a problem and it is why some manufacturers stopped allowing field calibration changes.

Not sure how to fix it other than by draining the pool and refilling to get down to the recommended level and then recalibrate the Jandy.


Sent from my iPhone using Tapatalk

 

[ping]

The pool does need to be drained to lower the salinity level no matter which test result you use. You could try removing about a third of the water and see what the SWG measures after the refill. I would trust the Taylor result the most.

Why was the SWG recalibrated? A sign that a SWG cell is starting to fail is reading a lower salinity level than the actual level.

 

[Russmd]

Thanks. I'll admit, I recalibrated the Aquapure salinity myself based on a significant difference between it and the test strips about 6 months ago.

I drained about a third of the pool yesterday and refilled with fresh water today. Just started it back up and have done nothing else chemically (I did take the opportunity to clean the grids and put in new DE).
Of note, my cell is only about 6 months old and the flow/salinity sensor is brand new.

I plan to let it circulate for 24 hours before I do anything else. Then... what do you suggest? Should I recalibrate the Jandy to the number I get with the Taylor reagent test kit and go from there?

Thanks,
Russ

PS: We're in a quandry as to why my salt levels shot up despite not having added any salt in over a year. Also, no other significant chemical additions other than acid. All I can come up with is that it's really hot here and there's obviously a lot of evaporation. I'm told our local water source has pretty high salt concentrations right now due to the drought - could this evaporation and concentration really raise the level like that?

Thanks again.

 

[JoyfulNoise]

I'm not familiar with the Jandy units to know what's involved in a recalibration. Typically SWG's are calibrated in the factory for a given salinity and water temperature. Some SWG's are temperature compensated, others are not. I'll say your proposed plan is probably the best place to start. The K-1766 ought to give you the most accurate salinity value.

As for what caused your increased, that's hard to say. Chlorinating liquids (and bleaches) all have both excess lye and salt in them. The addition of acid and its neutralization creates salt. All of those are fairly slow in their build up of salt. If you suspect your fill water is problematic, you could always check it to see what the salinity is. Knowing that value may help in determining if evaporation is the cause.

 

[Russmd]

Thanks. Calibrating the Jandy Aquapure is easy - just a key sequence and it allows one to adjust the value. Later today, I will reset it using the K-1766 as a reference.
Our water here is very hard. We have to use a lot of acid, especially in the summer months. As far as the salinity of the fill water, I tested it and it and it came out around 300. I called my water company and they said the water in my area could go as high as 1000 this time of year and with the drought! Wonderful.
Thanks again.

PS: Joyful Noise - I grew up in Tucson, NE side near Sabino Canyon.

 

[JoyfulNoise]

I believe there are ways to calculate, roughly, how much water loss you can get from evaporation using available meteorological data. Chem geek has done it in the past for people that believe they have excessive evaporation and fill. If you update your profile with your location (city, state) and you add some details to your signature, then it's easier to figure out.

Well, hopefully you're salinity is down to a level closer to ideal for your Jandy. I'm not sure if regular calibration is required for Jandy's but I do know my Pentair does not allow (new models don't allow field calibration). I read that this was done because too many pool owners would play with the calibration to make errors go away or to get the salinity output to make their test measurements and that would wind up causing problems with the salt cell. Does the Jandy need/require regular calibration?

Yes, I live out on the eastside past Houghton Road in horse farm country (well, not anymore, homes are popping up like mushrooms out here). Sabino Canyon is only a few miles away and we love to hike up there. With the last few rainstorms, the washes and streams are starting to fill up and the foothills are turning green. One more month or so of hot weather and then we'll be in my favorite time of the year - cool Fall months.

 

[Russmd]

Thanks for the help. I'll update my info. To my knowledge, the Jandy does not require regular calibration, but since I may have thrown it off before, I'll confirm it this once.

I know your area well. I remember back when Speedway was a dirt road past Pantano and Houghton was the end of the world. I spent my first 25 years in the Old Pueblo. I was in the opening class at Sabino HS, graduated UA, and am a Wildcat for life.

Best,
Russ

 

[Russmd]

Ok. Emptied about 3/4 and refilled. Salinity now at 2.0 confirmed by 3 different methods. Jandy was at 1.7 so that's been reset to 2.0. I'm starting off slowly, one bag of salt at a time and waiting 24 hours in between. After first bag, at 2200. I added stabilizer and some shock too since there's no chlorine right now and the generator is off till I get the salt up.
I know the recommendations are 3.0-3.5 but I'm thinking of stopping at 2.7 or 2.8 and seeing if it still has a tendency to rise on it's own.
Thanks,
Russ

 

[JoyfulNoise]

What's the lower limit on the Jandy?

Also, do you have an auto fill?


Sent from my iPhone using Tapatalk

 

[Russmd]

Jandy recommends 3-3.5. The error condition will turn on and disable the SWG at 2.0. At 2.5, it displays "low salt" but still functions. I do have an auto fill which is built-in; its origin is at a pvc junction with the line to my sprinkler valves.

 

[JoyfulNoise]

Jandy recommends 3-3.5. The error condition will turn on and disable the SWG at 2.0. At 2.5, it displays "low salt" but still functions. I do have an auto fill which is built-in; its origin is at a pvc junction with the line to my sprinkler valves.

Ok, 2800ppm could get a bit low when the temperature drops. I don't know if the Jandy compensates for temperature but if it doesn't then you can easily get a 400ppm drop in the salt sensor when the water is cold. No big deal, better to be low than high.

I asked about the auto fill because you mentioned having high salinity fill water. You might want to disable it and go to manual fill in order to measure usage. That way you could see if the high salinity fill water is going to affect you. Just a thought.


Sent from my iPhone using Tapatalk