What's more accurate for testing salt level?

LordDunlow

Active member
May 31, 2017
29
Melbourne, FL
We've had a ton of rain lately and I've had to drain a lot of water from the pool. Finally have temps high enough for the SWCG, but now it's saying low salt. The Hayward T15 says I'm at 2200 ppm, but a test strip (from the TFP ordering site) reads 1700... That's quite a bit of a difference. Which should I go with to decide how much salt to add? I'm guessing I'll use the higher number so I don't overshoot when calculating how much to add, but I'd like to know which one is more accurate.

Thanks
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
31,039
Laughlin, NV
The accuracy and resolution of each method are in the range of your difference. SWCG's tend to show lower than actual salt content in cold water. So I would suspect the strip is 'closer' - but - I would agree with you to use the higher number for your add. Better would be to get a K1766 salt test kit from TFTestkits.net.

Take care.

Whoops - flip flopped your numbers in my head! It is odd the strip is showing lower. I would be careful on adding your salt. And be sure the pool is well circulated when testing for it.
 
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YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
13,833
Evans, Georgia
I never trust the device to be correct. I only go by my Taylor K-1766 Salt Test Kit.

Is your device making chlorine? If so -it doesn't matter what numbers you're getting 'cause it's happy!

But I still like to know myself how things are. Hence I test!

Maddie :flower:
 

JamesW

TFP Expert
Mar 2, 2011
19,775
Be aware that there is an average salinity reading and an instant salinity reading. You want to go by the instant salinity reading.

How old is the cell? (The 3rd and 4th digits are the year of manufacture). For example, a serial number starting with 3E13 was made in 2013.
 

shingles

Bronze Supporter
Jun 12, 2017
270
Houston, TX
For what it’s worth, my Pentair T60 cell can show as much as 400ppm lower in colder water. Above 65, it is closer to actual as measured by K1766 numbers. If you must go by what your cell is saying, I would wait to add more salt till your water temp is closer 70*.