Salt level in a NON salt pool?

[oldguy70]

Tested w/Taylor 1766 kit....3200 in a NON salt pool

Have not seen any information on any issues, but over this year March-October I have added about 25 gals of chlorine (12.5%) which does figure to around 500 (edited) or so.

Any concerns?

 

[JamesW]

25 gallons or 25 jugs?

25-2.5 gallon jugs would only raise salt by about 1285 ppm.

Commercial pools on liquid can see 3,000 ppm salt from using liquid chlorine over a long time. But a residential should usually not get that high.

 

[Divin Dave]

There isnt any concern with that salt level, other than incresed possibility of acccellerated corrsoion. It's certainly a curiousity though, how it got that high.

 

[oldguy70]

25 gallons or 25 jugs?

25-2.5 gallon jugs would only raise salt by about 1285 ppm.

Commercial pools on liquid can see 3,000 ppm salt from using liquid chlorine over a long time. But a residential should usually not get that high.

25 gals of 12.5% chlorine....I have checked with the 1766 numerous times and the salt level checks 3000-3200 and yes if you calculate pool math it 25 gals should be about 500...I have no idea where all the salt level is from and I believe I am doing the 1766 test correctly.

 

[JamesW]

Can you test your fill water and post that number?

 

[pabeader]

I have been recently told that softened water can add salt to a pool if used for fill up or top up.

 

[JamesW]

Softeners add sodium but not chloride. A conductivity meter would register the sodium. However, the 1766 is specific to chloride and wouldn't show an increase.

 

[pabeader]

pools have chlorine in them? Isn't salt NaCl?

 

[JamesW]

Any form of chlorine adds chloride as the chlorine is used up. Some softeners exchange sodium for calcium. Added sodium from a softener wouldn't register on a chloride specific test.

Also note that there is almost no actual "salt" (NaCl) in a pool. It's mostly sodium and chloride ions.

 

[oldguy70]

Can you test your fill water and post that number?

My auto level fill is soft water (I forgot, I am old)....Just tested...1 drop turns to a milky yellow, 2 drops turn to a solid red color....estimate 150 ppm??.......initial water fill in March bypassed soft water.

So would I have added 500 ppm salt with chlorine and 2700 ppm with my auto water level fill? I suppose that is reasonable.

 

[JamesW]

The softener should not make that big of a difference. I'm guessing test error or somehow a lot of salt has been added.

 

[JoyfulNoise]

If you're doing the test with a 10mL (edit) sample size then each drop of silver nitrate corresponds to 200ppm chloride. So two drops to turn to milky salmon (not the final brick red) would be 400ppm chloride in your fill water. Is your source city water? If so, what does the latest water report indicate for salinity level?


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[oldguy70]

The softener should not make that big of a difference. I'm guessing test error or somehow a lot of salt has been added.

I am the only person who could have added salt, and other than the water level fill, the chlorine I have added. This was a fresh fill in March this year, and I have kept close track of chemicals. and the only one who has added since fill.

I am testing with the Taylor K1766....I take a fresh water sample, fill to the 10ml mark, using the speed stir add 1 drop of the R-0630, it turns a light yellow, add R-0718 (edited) 1 drop at a time holding vertical at a rate of about 1 second each drop, watch for the first sign of color to a salmon color and stop the drops before any brown or red color...I get 16 drops of R-0718 (edited) x 200 = 3200

If I am doing something wrong please let me know or maybe reagents are bad, kit is only 2 months old reagents are good to 4/17 & 8/16 respectively. I have a high CYA because of my stupidity of following pool store for the first couple of months of March & April before finding you guys. I also have an issue with the pebble and the builder, this fall/winter it sounds like we will be doing a drain & repairs (I hope it does not become a bigger issue)...I then can start over on the water and get the CYA under control and follow the TFP to a tee, anyway, if anyone has any other ideas on the salt thing?

 

[JamesW]

I think you mean R-0718?

Something's off, not sure what. Either bad test or salt added or maybe something else?

Are you sure that you're not filling to the 25 ml line?

If you were using the 25 ml line, that would make your salt 1280 ppm, which would be close to the 1285 ppm from (25) 2.5 gallon jugs of 12.5%, which would be about the amount of liquid chlorine needed over the time period.

 

[JoyfulNoise]

Is your pool covered? We here in AZ have very high evaporation rates. In my area (Tucson), the average annual pan evaporation level is 111" of water or about 9ft of water per year. So water source chemistry makes a huge difference if the pool is uncovered.


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[oldguy70]

I think you mean R-0718?

Something's off, not sure what. Either bad test or salt added or maybe something else?

Are you sure that you're not filling to the 25 ml line?

If you were using the 25 ml line, that would make your salt 1280 ppm, which would be close to the 1285 ppm from (25) 2.5 gallon jugs of 12.5%, which would be about the amount of liquid chlorine needed over the time period.

Sorry, you are correct R-0718, and I am using the 10ml mark.

- - - Updated - - -

Is your pool covered? We here in AZ have very high evaporation rates. In my area (Tucson), the average annual pan evaporation level is 111" of water or about 9ft of water per year. So water source chemistry makes a huge difference if the pool is uncovered.


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No cover, yes auto level runs most of the time, a steady dribble or whatever.

 

[JamesW]

I would suggest a different salt test to confirm and/or a salt standard solution to check the test.

 

[oldguy70]

If you're doing the test with a 10mL (edit) sample size then each drop of silver nitrate corresponds to 200ppm chloride. So two drops to turn to milky salmon (not the final brick red) would be 400ppm chloride in your fill water. Is your source city water? If so, what does the latest water report indicate for salinity level?


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Yes 10ml x 200 to milky salmon, 1 drop was milky yellow, 2 drops brick red...so maybe 300 ppm

city water, can't find exact specs, but I understand the chloride is very low.

 

[chem geek]

Did you add acid to lower the pH? If so, that adds to chloride. Every gallon of full-strength Muriatic Acid (31.45% Hydrochloric Acid) added to your pool increases salt by 56 ppm (in ppm NaCl units).

Also, the absolute chloride level is pretty meaningless if you didn't test it at the start of this year or end of last year. In other words, you may have started with a high level.

25 gallons of 12.5% chlorinating liquid in 10,500 gallons is 298 ppm FC which from mid-March to mid-October so around 210 days is 1.4 ppm FC per day. That sounds low to me. That would increase salt by around 500 ppm. If your actual chlorine usage were more like 2.5 ppm FC, then it would be more like 1000 ppm salt added.

 

[oldguy70]

Did you add acid to lower the pH? If so, that adds to chloride. Every gallon of full-strength Muriatic Acid (31.45% Hydrochloric Acid) added to your pool increases salt by 56 ppm (in ppm NaCl units).

Also, the absolute chloride level is pretty meaningless if you didn't test it at the start of this year or end of last year. In other words, you may have started with a high level.

25 gallons of 12.5% chlorinating liquid in 10,500 gallons is 298 ppm FC which from mid-March to mid-October so around 210 days is 1.4 ppm FC per day. That sounds low to me. That would increase salt by around 500 ppm. If your actual chlorine usage were more like 2.5 ppm FC, then it would be more like 1000 ppm salt added.

Yes everyday I add acid 29% or 31.45% (whichever I buy on sale)...started @20 oz per day, now about @12 oz per day to keep pH 7.5-7.7

Start of the year in March, resurface new fill, used tabs March & April, switched to TFP in May using 12.5% liquid chlorine....I may not have calculated exactly how many gals of chlorine, but I think I am very close, have high CYA was using about 2.5-3.0 ppm in the dead of the sun/heat, now down to 1.2-1.5 with water temp @75, much less sun etc.

I have added several gals acid since March, I would be guessing but I was going through a gal a week for several months...so if I have gone through at least 20 gals of 31.45% x 56 ppm salt = 1120 ppm....would this be correct?