Where's the salt!! Help......

[George in Georgia]

A little help, please!

I am in the process, thus far successfully, of clearing my green pool.

Here are the latest quick and dirty test results:

Cl 3ppm
TCl 5ppm
Alk 150
pH 6.5
TH 100
CyA under 40 This from a test strip. The water is still a little cloudy for the solution test, I think.
Temp 81 F

These results are about 20 minutes old. This morning the readings were about the same, but Cl was 5ppm

Vinyl liner, about 22,000 gallons, Hayward salt water generator. The cell is perhaps 3 years old.

Running the generator essentially 24/7, and adjusting pH and adding CyA the pea-green algae is gone.

Now the puzzler. I had kept the salt level per the generator at 3000 or 3100 ppm, depending on recent rain, etc. The day before yesterday the level showed at 2600, so I added some salt. Yesterday I started with a clarifier from Leslie's, which I've used successfully in the past. This morning the pool was much clearer. We were away til about 4PM. I checked the salt, and the generator said 2000 ppm, and it had shut down. I tried two salt test strips, one was inconclusive; the other said 400mg/liter, which is about 400 ppm. This sort of drop is absurd!

I really hesitate to add more salt! As I understand the chemistry of the process the only significant decrease in salt level would result from dilution from rain, or by backwashing and adding makeup fresh water.

What could have happened? I'll try cleaning the cell, although I'd expect a gradual drop off in output rather than .... whatever. I guess I'll take a sample to Leslie's.

Anyone have any good ideas??

 

[4knights]

The salt won't just disappear unless the water does as well or its diluted from lots of rain. My guess would be
1. the test strips are either old or purchased new but an old lot still on the store shelf.
2. The salt cell may not be calibrated.
3. The original reading of 3100 was not correct due to out of calibration cell/ test strip
4. You're letting the pool store do your Testing( bad idea- they sell what they need to sell)
Or
Morton stole your salt. ( just kidding)

Get a good test kit, begin testing so YOU know the real info. Pool School is your friend(read)

Add your info in the signature line so folks can provide more accurate info. Type, brand, etc. ¥¥¥

 

[duraleigh]

Are your other test results from strips?

Your bigger issue is pH, not salt. Depending on how much you trust that pH test, (not at all if it's strips) your pH needs to come up into the 7's---sooner rather than later.

Your water is not too cloudy for the turbidity test to check CYA. What made you think it was?

So, I know you didn't ask about the stuff above, you asked about false salt readings. If you had a reading of 3100 and were making chlorine, then your SWG is giving a false reading of 2000.......salt does not leave a pool like that.

I can't say that your clarifier had anything to do with that, but I can tell you we don't like clarifiers so we have little experience with any side effects.

I know this is coming of pretty negative but you are doing a lot of things that TFP does not think is the best path. Trying to clear a green pool with the SWG is not a good idea. Clear your pool with liquid chlorine and give the SWG a rest.

Cleaning the cell is the best idea. Others with more SWG experience than I will be along to suggest other things

 

[George in Georgia]

The salt won't just disappear unless the water does as well or its diluted from lots of rain. My guess would be
1. the test strips are either old or purchased new but an old lot still on the store shelf.
2. The salt cell may not be calibrated.
3. The original reading of 3100 was not correct due to out of calibration cell/ test strip
4. You're letting the pool store do your Testing( bad idea- they sell what they need to sell)
Or
Morton stole your salt. ( just kidding)

Get a good test kit, begin testing so YOU know the real info. Pool School is your friend(read)

Add your info in the signature line so folks can provide more accurate info. Type, brand, etc. ¥¥¥

That Blasted Morton!!!!!! I use good old water softener salt from Lowe's, much cheaper than from Leslie's. And I make certain its just good old NaCl, no additives for Fe reduction, etc.

Re: Stale test strips: The two multipurpose strips both bear an expiration stamp of 8/15. One NaCl says 9/15, the other 12/16. All have been kept in the house, temperature controlled.

I had done a baseline test with an OT kit, the agreement with the test strips was pretty close, so I've used the strips for daily checks. The water until today has been too green/cloudy, I thought, for the solution test for CyA to be feasible. Additionally, getting replacement reagent locally is difficult.

The OT kit is fine, although the color judgments can be iffy. Makes me long for the burettes and proper reagents from my Qualitative and Quantitative Analysis chem course many, many years ago. But not the General Unknowns! Funny, a local pool store uses burettes, but I can see that they don't really know how.

Tests from the pool store? Only rarely, and only if I've done my own test just before theirs. I got tired of being told that keeping up high Ca was essential in a vinyl pool. I'm the sorta guy who built and repaired as necessary, two HeathKit color TVs, processes his own BW and color film, and did the majority of my own auto maintenance until I got tired of rust flakes from exhaust systems in my face.

The salt cell did fine last year. I intend to clean it tomorrow with HCl (always add acid to water, I know!) and see if that "fixes" things. If not, then a call to Hayward from beside the control box to check codes with them.

Tonight when the sun goes down I'll add a couple jugs of bleach, 8%, just to tide things over, since the free Cl is lower than this morning.

Thanks for the quick response. I'll keep folks up to date.

 

[Patrick_B]

The drop tests we suggest for pools will get you the results from the Burette titrations you long for. Even free Chlorine. Order yourself a good kit, along with a salt test kit. It's a drop count Chrome/Nitrate type That will give you accurate results. With a good kit, you can quit guessing, and you'll need it to clear the pool.

Welcome to TFP.

 

[duraleigh]

I would adjust your pH before I did anything else.

 

[Patrick_B]

Yes, get your pH into the lower/mid 7's right away, then order a proper kit.

 

[pooldv]

There are really only a few choices.
You need salt - unlikely
The cell is acting erratic because it is failing - possible
Bad sensor in the cell - possible

I like the option to call Hayward to run through the codes.

 

[George in Georgia]

Okay, I added 2 jugs of 8.25% bleach this morning. OT tests show:

pH 6.8 I'll fix this!
Cl 5 ppm
Tot alk 30ppm

Did the acid clean on the cell. Doesn't look good. Time for a call to Hayward.

BTW, thanks for the tip on a "titration" test for salt. I do wish that the OT tests for Cl and pH weren't based on matching a color patch. I get my wife to confirm my guess, she's a seamstress and used to fine color differentiation. But who can afford burettes and volumetric flasks.....

 

[George in Georgia]

I talked with Jason at Hayward, his feeling was that the cell, the serial number indicated it was a 2010 item, was probably dead. He suggested a local dealer with cell test equipment. I had it checked, and it failed. I've ordered a replacement which should arrive Thursday, in the mean time I'm using bleach. Never a dull moment!

Let's see ... last week clutch, flywheel, starter on the Frontier. This week the pool. Next week tires for the Mazda. And the hits keep coming!!

 

[pooldv]

dangit!