Why can I not measure salt accurately at home???!!!

[tlevy]

This is frustrating. My strips (AquaChek) are so far off the mark it is laughable. My T15 shows about 2800 ppm and PB is saying about 3000 ppm. My strip reads a out 1/4 of that...

My kingdom for an accurate at home test for salt!

Any thoughts/recommendations?


68,000litre, IG vinyl, LorentzPS 600 Solar Pump & 1/2 HP Tristar, Sandfilter, Aquarite T-15 SWG

 

[jblizzle]

Taylor K-1766 Drop test.

Although realize that the SWG and salt tests may be +/-200 at best.

From day 1 my Taylor test has been about 600-800ppm higher than what the SWG reports. So I just use it to see that the trends are consistent. Making the SWG happy is the goal.

 

[ping]

Test strips are not the best but are usually reliable enough for salinity readings. Yours are either junk or you are not following the instructions properly. My guess is that your strips are no longer reading correctly.

The best salinity test is the Taylor K-1766, but I'm not sure where you can get this kit in Canada.

For now, rely on the SWG reading as that is what matters most. If you are in doubts about the salinity and are troubleshooting the SWG, then it is best to have a reliable salinity reading.

 

[tlevy]

Thanks both!


68,000litre, IG vinyl, LorentzPS 600 Solar Pump & 1/2 HP Tristar, Sandfilter, Aquarite T-15 SWG

 

[Griswald]

If your SWG tells you 2800 (and remember, that is a 24 hour average, not an instant reading) and it is happily producing chlorine, there really is no need to know what the exact number really is. 2800 is about what mine tells me no matter what I test the actual salt level to. Sometimes it will go up to 2900 for a while, but I learned to live with whatever makes the device happy.

 

[mikemass]

Earlier this year, I overshot my Salt. My SWG was going bad and reading low. But I didn't know that at the time. So I kept adding salt. Eventually I realized that the cell was going bad after dumping what I knew was WAY more salt than I should have. Having never bought a home test for salt (because by all reports here they are all very inaccurate), I brought a water sample to a few local stores. Leslies said I was at 4500. A "high end" Pool Store by me said 4000. Based on what I know I normally need in the spring and what I actually added, I think Leslies was more accurate.

End of story - I dumped some water, got a brand new T-15. My system reads 3800. Mr. "High End Store" now says I'm at a "perfect" 3400. My SWG system is happy and working tremendous. So I am not touching it!

 

[tlevy]

Good points. I did get a low salt/inspect cell light. After I cleaned it, the ppm reading went higher and the light went out....


68,000litre, IG vinyl, LorentzPS 600 Solar Pump & 1/2 HP Tristar, Sandfilter, Aquarite T-15 SWG

 

[chawkins99]

How are you using the test strips?
You should put the bottom of the strips in the water (no more than 1 inch) then wait for the top indicator strip to change. I was almost fully submerging the strips and that gave a false low. I ended up with way too much salt and had to do a partial drain to get it back down. I just rely on the SWG display now.

 

[ping]

I would go ahead and add two 40lb bags of salt to the pool if it were mine. This should raise the salinity by around 500 points and put the salinity in a better range. At 2600, the T-15 has issues and it is best to avoid low salt conditions.

 

[tlevy]

How are you using the test strips?
You should put the bottom of the strips in the water (no more than 1 inch) then wait for the top indicator strip to change. I was almost fully submerging the strips and that gave a false low. I ended up with way too much salt and had to do a partial drain to get it back down. I just rely on the SWG display now.

I was doing just that! The instructions are not clear in that regard. Will try your method and see if it helps.


68,000litre, IG vinyl, LorentzPS 600 Solar Pump & 1/2 HP Tristar, Sandfilter, Aquarite T-15 SWG

 

[JamieP]

This is interesting... Which salt reading should be used in Pool Math to contribute to the CSI result? The one that shows up on the SWG or the one gained through testing?

 

[jblizzle]

It does not make a big enough difference to matter.

 

[JoyfulNoise]

This is interesting... Which salt reading should be used in Pool Math to contribute to the CSI result? The one that shows up on the SWG or the one gained through testing?

If you're using the K-1766, then use that value for pool math. Pool Math takes into account all the contributions to TDS to do the math required for the CSI calculation so the user can just enter in values straight from their test kits without having to calculate any "adjusted" parameters.