Salt tests - Inaccurate! Meter & Strips!!!!!

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nauidvr1

nauidvr1

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Jun 8, 2009
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I am in the need of a accurate and reliable Salt testing method. I would like the forum members input - I am looking at the Taylor K-1766 or a Digital meter (I don't mind calibrating it or the cost).

I have read every post I could find on hand held digital salt testers (LaMotte & Goldline) and do understand there limitations and need for calibrating. I would also like some input on the Taylor K-1766 Salt test kit.

I currently use the AquaCheck test strips I ordered from TFTestKits last year (they provide the same results as new ones), but have been having real issues comparing it to anything (double checking my results). I have a friend (my neighbor) that works at a local pool store, that uses a Goldline Salt test meter, and recently their meter stated I had 2.3ppt (2300) salt level, when my test strips showed a reading of 4800. I asked them to open a brand new container of AquaCheck Salt test strips and do a side by side test. But first I asked (and watched) him calibrate the Goldline salt meter in a 3.2ppt calibration solution. Once calibrated we did a test with both the brand new salt test strips and the freshly calibrated meter (was only off by 0.1). Results were the same – meter read 2200 and the strips read 4800.

So my dilemma is what is the most reliable way to test? Cost is not a concern, I have no problem purchasing a LaMotte or Goldline salt meter, along with a calibration solution, if it gets me accurate results. I just want accuracy I can believe! I would not have an issue if the test were only 500 ppm off from each other, but 2500 ppm is too much, as it could cause me to over salt or under salt my pool. In fact, it did cause me to over salt the pool, that's how my salt got to 4800 (per the test strips). Last week there salt meter results for my salt level was 1100. So I used the Pool Calc to find out how much salt to add to bring my pool up to 3500-3600. Once I added 520 lbs of salt, brushed and dissolved, two days later their calibrated salt meter stated 2200 & my test strips said 4800. Which do I believe? I just need to be able to believe the results I get, no matter how I got them!

Thanks for any input!
 
What matters is what the SWG thinks the salt level is, not what the salt level "really" is. If the salt is there so the SWG will work, it is the SWG that matters, not what any of the test says. If the Intellichlor is happy with the salt level, then leave everything alone!

The Taylor K-1766 test is the most reliable test available, if you know how to use it. It can be a pain to use, and beginners often misunderstand the directions and get incorrect results. Also, one of the reagents in the test can cause stains on your fingers that won't go away until your skin wears away and is replaced by new skin.

Some of the better meters are more precise than the Taylor K-1766, but they do drift and they can be fooled by some rare kinds of water contamination.
 
I agree with Jason on all points. Go by the SWG. The test kit is useful if you suspect something is wrong with the cell. I use the test kit maybe once a year just to keep tabs on the cell. They seem to track each other fairly well and will usually read within 200 ppm of each other. I will know that the SWG is starting to fail when the salt level readout is much lower than the test kit. However, a dirty cell will also tend to read lower salt so if you notice a drop off in the salt reading, check the cell to make sure it isn't dirty.
 
I find it helpful to keep a log to track of all the things that I put in the pool- water, salt, borate, bleach, etc...I have an advantage in that I just emptied/refilled last year (twice! thanks to the pool "professionals",) so I know how many gallons of water it takes to raise the pool level one inch( 400 gal. for me,) and I know that my starting points for salt, and borate was 0. If you have an auto fill, put a meter on it, it will pay for itself the first time you catch a leak before the water bill comes.

If the pool has not been used much( little splash out,) I haven't back washed the filter, and I don't think that there is a leak, then the concentrations won't change when filled back to "normal" level.
Replacing water due to splash out, leaks or back flushing will reduce the concentrations, but a little math and the pool calculator will put you right back where you want to be, enjoying a cool cocktail next to a Trouble Free Pool! :goodjob: ( Use the Pool Calculator - http://www.poolcalculator.com/, put in the amount of water added as Size, starting levels of 0 for Now ((unless you KNOW that your water company salts its water, adds borate, etc..)) and put in your Target (3500???) and the PC will tell you how much to add (12 pounds of salt for every inch of water, in my case.)

You don't need to re-fill to get a starting point, however. Just get numbers you believe in and go forward with them. If the ECG is happy today, so should you be.
If the ECG is unhappy tomorrow, and nothing has changed in the pool, clean/re-calibrate/repair/replace it, but don't mess with the water.
Good Luck, and Best Wishes!!!
 
Too All,
I get what your saying, but I want to know my salt level before I even put the SWCG in-line. I remove the SWCG and replace with a dummy cell at pool closing.

Case in point: This year during the winter I lost 24 inches of water due to a small seepage leak from around the light fixture. So I filled the pool to the correct level during the winter (during the big snow storm in the mid Atlantic region) and then finished topping off when opening. I wanted to know how much salt I lost, so I would know how much to put back in to bring to correct SWCG startup level. During all of this salt testing I have found that this year the Aquacheck salt strips are unreliable (both my stock of them and a brand new bottle - which reads the same). This sucks when your attempting to find your current level and adjust to the correct level for SWCG startup. I am a bit anal about my numbers, and my pool shows it during the season. Hence the reason for wanting a GOOD, RELIABLE way of testing for salt. Thanks for everyone's input.

P.S. I use the Pool Calc so much I even bought the iPhone Pool Calc App so I have it poolside!
 
TripleB4me said:
You can just order the reagents for the Taylor salt test kit, ~$15.00 and print the instructions from their website. It appears to be a very simple and accurate test.
Click to expand...

EDIT: Found the instructions - the Taylor website isn't the best I have ever seen.....
 
JasonLion said:
The Taylor K-1766 test is the most reliable test available, if you know how to use it. It can be a pain to use, and beginners often misunderstand the directions and get incorrect results. Also, one of the reagents in the test can cause stains on your fingers that won't go away until your skin wears away and is replaced by new skin.

Some of the better meters are more precise than the Taylor K-1766......
Click to expand...
JasonLion,
Can you be more specific on "It can be a pain to use", as the instructions seem very straight forward to me, see below. Also can you state what meters your referring to specifically by name, in the less than $250 range?

1. Rinse and fill sample tube to 10 mL mark with water to be tested.
2. Add 1 drop R-0630 Chromate Indicator. Swirl to mix. Sample should turn yellow.
3. Add R-0718 Silver Nitrate Reagent dropwise, swirling and counting after each drop, until color changes from yellow to a milky salmon (brick) red. Always hold bottle in vertical position.
NOTE: Do not add enough R-0718 Silver Nitrate Reagent to give a brown color. First change from yellow to a milky salmon (brick) red is the endpoint.
4. Multiply drops of R-0718 Silver Nitrate Reagent by 200. Record as parts per million (ppm) salt as sodium chloride (salt water).
 
For a digital meter, the Lamotte Salt Pocketester is fairly good. There are many of them, I have only tried out a few.

On the K-1766, any time Taylor includes a "NOTE:" tag you know something is up. It isn't really a big deal, you will learn to do it quickly enough. Just read that note and pay attention while doing the titration.

All your concern about the actual salt level isn't going to help your pool at all. It is probably a fun hobby, but it isn't about taking care of the pool. If you want to take care of the pool, stop worrying about what the salt level is and trust the SWG. The SWG is actually better at knowing what it wants than any salt test ever will be.
 

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FWIW, I found the strips to be inaccurate as well. In my case, I had two bottles of test strips that were giving me different results, so I purchased the Taylor kit to see which one was fibbing to me, and decided to keep using the Taylor kit, and say goodbye to the test strips. I do agree with Jason and mas985 that the main priority is making sure the SWG is happy with the salt level, but like you, I'm anal about such things, plus I try to keep my salt level as low as I can and still keep the SWG happy.

The Taylor kit is pretty simple to use, just take heed of the precautions already mentioned about the titrant indelibly staining your fingers, and also clean your test vial after each use (take a small bit of paper towel and scrub off the residue left on the inside of the vial).
 
Yes, you end up using twice as many drops compared to a 10 ml sample size so each drop counts as 100 ppm instead of 200 ppm (technically, the line in the tube is at 20.5 ml, not 20 ml, but that's close enough). I use the 25 ml sample size where each drop is 80 ppm, but that is of course a little harder to figure in one's head.
 
chem geek,
Thanks for the info. I just ordered the Taylor K-1766 from TFTestkits along with some other refills. I will try both ways of testing and see which I prefer.
 
Wow I love this site ... been lurking awhile, but alway seem to find what I need.

I do have one clarifying question. I just got the Taylor K-1766 kit and was adding some salt over the last couple days. I was also wondering if I could make the test more accurate (<200ppm per drop). So, if I go with the 20 ml sample, do I add 2 drops of the yellow R-0630 Chromate or still just 1? Then each drop of R-0718 Silver Nitrate Reagent is 100 ppm.

The statement of using a 25 ml sample confused me as I could not figure how you could put 2.25 drops of the R-0630 in to get the 80 ppm per drop.

Thanks
 
jblauert said:
The statement of using a 25 ml sample confused me as I could not figure how you could put 2.25 drops of the R-0630 in to get the 80 ppm per drop.
Click to expand...
As Jason noted, you don't have to scale up the indicator dye amount for the sample size. When I use a 25 ml sample size, I just use 2 drops of R-0630 so that the color is very rich and easy to see, but it's not really necessary. The 80 ppm per drop is for each drop of titrating reagent, R-0718.
 
JasonLion said:
What matters is what the SWG thinks the salt level is, not what the salt level "really" is. If the salt is there so the SWG will work, it is the SWG that matters, not what any of the test says. If the Intellichlor is happy with the salt level, then leave everything alone!
Click to expand...

It's frustrating that the intellichlor, for example, cannot be calibrated.
 

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