Do salt test regents go bad? Strange results.

[popechild]

Had to drain and re-fill pool so I'm starting from scratch on the salt. Looking to get to ~3500. Tested with my K-1766 test kit (which I've had for a few years now) and confirmed a 0 reading before adding any salt.

PoolMath said I'd need to add about 380lb for my 13k gallon pool. I added 240lb to start, which only raised the level to 600. Added another 160lb (for 400lb total), which only raised the level to 1600. My SWG (a Circupool SJ-35) doesn't give a numerical reading, but has a salt light that turns on if salt level is too low. That light is on.

Water temp is about 65.

Probably should have thought about the possibility of bad test regents before, but between the low results and the light on the SWG, I figured it was still low and I added another 160lb of salt last night. SWG light is still on and new test this morning only shows 2200. That's 560lb of salt, which should be way too much.

Wondering if I overdid it due to bad results from my K-1766 kit. Do these regents go bad? It's been stored indoors on a shelf, so not exposed to extreme temperatures or anything.

 

[ajw22]

Confirm you are testing using a 10ML water sample and not 25ML?

Your results seem to be 2.5X less than expected. It is a common mistake.

Otherwise buy a new test kit and let us know what difference you find.

 

[JoyfulNoise]

Salt can take a long time to dissolve and homogenize in the water column because salt water is more dense than pure water. It can take up to 48 hours with the pumps running (and brushing) to adequately mix the water. It’s even harder when the water is cold.

My guess is you were getting low readings from the water not being fully mixed.

 

[Bperry]

Confirm you are testing using a 10ML water sample and not 25ML?

Your results seem to be 2.5X less than expected. It is a common mistake.

Otherwise buy a new test kit and let us know what difference you find.

I’ll second that, done it many times.

 

[popechild]

Confirmed I’m testing at 10ml. Went to Leslie’s just now and had them test it and they got 4000, so it does appear my test is giving bad results. The first 400lbs of salt has been in the pool (circulating and with dolphin running a few times( for a good 3-4 days so I’m assuming my regents must be bad.

Going to buy another test kit and hopefully that will give the expected results.

And I guess I get to replace some of my water now that I appear to have overshot it on the salt due to the bad results.

 

[ajw22]

560lbs of salt in 13,000 gallons should give 5200ppm.

4000ppm would say you have 17,000 gallons.

I don’t trust the result you got from Leslie. Something is still off in your water volume, salt added, or testing.

 

[Mdragger88]

Confirmed I’m testing at 10ml. Went to Leslie’s just now and had them test it and they got 4000, so it does appear my test is giving bad results. The first 400lbs of salt has been in the pool (circulating and with dolphin running a few times( for a good 3-4 days so I’m assuming my regents must be bad.

Going to buy another test kit and hopefully that will give the expected results.

And I guess I get to replace some of my water now that I appear to have overshot it on the salt due to the bad results.

You’re good - no need to exchange water.
From the manual
The CircuPool SJ-Series can work within a broad salinity range, from a minimum of 3500 ppm (parts per million), to upwards of 5000 ppm. However, the ideal level for operation is around 4000-4500 ppm.

https://www.discountsaltpool.com/assets/doc/CircuPool-SJ-Manual.pdf

Just get some new reagents & confirm your results - they have a shelf life of 2 years- some may last a little longer if stored properly.

 

[ajw22]

Is your SWG happy or still showing low salt?

At your salt levels the SJ30 should be generating.

 

[popechild]

You’re good - no need to exchange water.
From the manual
The CircuPool SJ-Series can work within a broad salinity range, from a minimum of 3500 ppm (parts per million), to upwards of 5000 ppm. However, the ideal level for operation is around 4000-4500 ppm.

https://www.discountsaltpool.com/assets/doc/CircuPool-SJ-Manual.pdf

Just get some new reagents & confirm your results - they have a shelf life of 2 years- some may last a little longer if stored properly.

Interesting. The manual online shows 3000-4000 with ideal 3500 (see screenshot) but I called Circupool and they said that's incorrect and 4000 is a good number.

I left the system on for a while longer and the Salt light turned green finally, so maybe it just needed to get warmed up to get a better reading. Happy I didn't (apparently?) overshoot the target, and seems like I still need a new test kit.

I do agree the 560lb should have raised it to more than 4000ppm, so still not sure what happened there. I know I added 14 x 40lb bags of salt, but I didn't manually weigh them. I did order a 40lb box of calcium chloride the other day that I did weigh and it was actually only 26lb so maybe the bags weren't really 40lbs? Or the pool store's measurement is also off and my number is higher. Don't see any way to get to 17k gallons based on calculations of the measurements of my pool. And something between 13k-13,500 gallons has typically always worked as expected when adjusting chemicals based on that estimate. This is the first time it seems way off.

I'll try to report back when I get the new Taylor test.

 

[mc2021]

Last year I added salt when the water was in the 60's and my robot was picking up salt for 4-5 weeks after that was not dissolved. I now dissolve it in a 5 gallon bucket first. Takes more work but I won't overshoot the target again.

 

[Mdragger88]

Interesting. The manual online shows 3000-4000 with ideal 3500 (see screenshot) but I called Circupool and they said that's incorrect and 4000 is a good number.

I left the system on for a while longer and the Salt light turned green finally, so maybe it just needed to get warmed up to get a better reading. Happy I didn't (apparently?) overshoot the target, and seems like I still need a new test kit.

I do agree the 560lb should have raised it to more than 4000ppm, so still not sure what happened there. I know I added 14 x 40lb bags of salt, but I didn't manually weigh them. I did order a 40lb box of calcium chloride the other day that I did weigh and it was actually only 26lb so maybe the bags weren't really 40lbs? Or the pool store's measurement is also off and my number is higher. Don't see any way to get to 17k gallons based on calculations of the measurements of my pool. And something between 13k-13,500 gallons has typically always worked as expected when adjusting chemicals based on that estimate. This is the first time it seems way off.

I'll try to report back when I get the new Taylor test.View attachment 474363

You should always turn the cell off when making large salt additions (more than a bag or two that are far from the intake) as you risk a slug of very salty water going through your cell & damaging the sensors etc. Turn it back on once the addition has had time to circulate for a day.