Salinity: CircuPool & Taylor discrepancy

[P00LNerd]

Salinity has been measuring 3200 ppm by Taylor drop test, which is on the low end of the recommended 3k - 4k range, but fine. However, the controller on our freshly-installed CircuPool RJ-45+ is listing the salinity at 2900 ppm, out of range. The system is running, not faulting, but I guess I need to add more salt.

Is it common to see that much discrepancy?

Which is more accurate?

Is the CircuPool controller reading affected by flow rate or water temperature?

 

[HermanTX]

The Taylor K1766 test kit is the most accurate but also remember each drop is 200ppm so there is a +/-200ppm variable if you are not careful with your drop count.

Most every SWCG measure salt level using a conductivity method. Per our article on Salt, this is some info on Circupool

Discount Salt pools has said the following:

Like the Hayward, the Rj System measures salinity by determining the level of conductivity in the water. Anything that affects conductivity can trigger a low salt/check cell indicator. Some examples include low salt, dirty cell, air trapped in the cell or low water temperature. All of these things must be aligned in order for the system to calculate an estimated salinity level. Also, ensure 'cell type' setting has not been changed. Customers often unknowingly change the cell type altering the salinity level which in turn can also trigger a warning light. Any solid warning lights will shut off amps to the cell, meaning no chlorine production

 

[P00LNerd]

Thanks, HermanTX!

I assume that when measuring anything by Taylor drop test, it's the "go until it stops changing color, then subtract 1" method, right? I get first bit of red brick shade at 15 drops (3000 ppm), full change to red at 16 drops (3200), then no change at 17 drops.

I believe I saw the controller calling out the correct cell (RJ-45+), but will check again tomorrow. I didn't change it, just turned the thing on and hit menu a few times to see what it displayed. Pool temp is 84F, but water running thru the cell is 90F according to the controller. I suspect the water must actually be warmer than that at the cell, as the heater is running, but I could be wrong.

 

[Bperry]

Thanks, HermanTX!

I assume that when measuring anything by Taylor drop test, it's the "go until it stops changing color, then subtract 1" method, right? I get first bit of red brick shade at 15 drops (3000 ppm), full change to red at 16 drops (3200), then no change at 17 drops.

No. Its the first dramatic change from yellow to red.

 

[proavia]

If the SWG is happily making chlorine at the SWG indicated salt level of 2900, just leave it for now.

K-1766 salt test is complete when the color changes and stays a brick red color. It's a marked change - and if it doesn't get back to the previous color, you're done.

 

[P00LNerd]

No. Its the first dramatic change from yellow to red.

Hmm... this is how I was measuring Total Alkalinity, but was told these drop tests always work by when it stops changing color, then subtract the last drop.

 

[Bperry]

Hmm... this is how I was measuring Total Alkalinity, but was told these drop tests always work by when it stops changing color, then subtract the last drop.

Salt test is different. Got the instructions?

 

[Rancho Cost-a-Lotta]

 

[P00LNerd]

Salt test is different. Got the instructions?

I've learned from this forum that the Taylor test kit instructions can be lacking in specificity. Read the instructions for the TA test. You'll see it says nothing about going until color change stops.

Either way, result is same for salt, as color change from yellow to red is happening at 16 drops = 3200. At 15 drops, it is still yellow. When I say "hint" I mean just that, still nearly the same as the starting color, with just the slightest hint that it's starting to shift.

 

[proavia]

The other thing that gets many of us on the salt test is #1 in the directions.
"1. Rinse and fill the 25 ml sample tube (#9198) to 10 ml mark ..."
We see the 25 ml and stop reading.
Be sure to use 10 ml of pool water for this test.

 

[pjt]

I've learned from this forum that the Taylor test kit instructions can be lacking in specificity.

Agreed. The amplifying remarks are important. For the TA test, keep going until there's no further color change. For the salt test, when it makes the obvious change to salmon red, you're done. Are you using a SpeedStir?

 

[JamesW]

Speedstir is a big help.

 

[P00LNerd]

Yes, using SpeedStir. Total game changer!

Thanks guys. I'll redo the Taylor test today with photos, just so we can all agree.

Hey, weird question... does salinity drop when SWG is running? We're splitting NaCl, so in theory NaCl will be lower with SWG running, versus not. But with only 8 ppm FC, versus 3200 ppm NaCl, maybe the drop is too small to ever measure. I don't know the ratio of FC production to NaCl reduction, but assume it's at or near 1:1.

 

[JamesW]

But with only 8 ppm FC, versus 3200 ppm NaCl, maybe the drop is too small to ever measure.

 

[P00LNerd]

Okay guys, had a quick chance to re-test and photograph this morning. The photos start at 14 drops and conclude at 17 drops.



Severity of color change at 15 drops varies, as "drops" is not exactly a precision measurement, yesterday it was noticeably lighter than this. But full "red brick" did not occur until 16 drops.

 

[JamesW]

Maybe 15.5 drops = 3,100 ppm.

 

[JamesW]

Salinity has been measuring 3200 ppm by Taylor drop test, which is on the low end of the recommended 3k - 4k range, but fine. However, the controller on our freshly-installed CircuPool RJ-45+ is listing the salinity at 2900 ppm, out of range.

Within 400 ppm is considered to be good agreement.

 

[P00LNerd]

Cool. Good to understand.

Unless there's some advantage to be had by being right on the 3500 ppm nominal (lower electricity usage?), I'm inclined to just let it run as-is, as proavia suggested. The controller isn't complaining about low salinity, even though it's reading under 3000 ppm min spec.

 

[proavia]

Update your signature to delete or add equipment and test kit info.

https://www.troublefreepool.com/account/signature

 

[Bperry]

Okay guys, had a quick chance to re-test and photograph this morning. The photos start at 14 drops and conclude at 17 drops.

View attachment 598726 View attachment 598725 View attachment 598724 View attachment 598723

Severity of color change at 15 drops varies, as "drops" is not exactly a precision measurement, yesterday it was noticeably lighter than this. But full "red brick" did not occur until 16 drops.

16 drops picture is what it looks like but Ive never see that 15 drop picture before. Its always a sudden and dramatic switch from picture 14 to 16. Id be curious what picture 15 looks like as it continues to mix.