Salt PPM changing on me, why?

Angnjam

0
LifeTime Supporter
Oct 8, 2013
69
Southern California
The low salt light came on on my swg yesterday. So yesterday I tested the salt content with the K-1766 salt test kit and it was 2800 ppm. It was 3200 ppm last week. This morning the light went off and I tested it again, it is at 3000 ppm. So what is going on with my tests and water? Why is it fluctuating like this. I was going to shock the pool, because I thought it was getting a little cloudy, but I ran the pump for a couple more hours a day and added about 2 quarts of liquid chlorine and a gallon of muriatic acid (which I probably added too much because the PH reading is now at about 7.3). It brought my FC level from .5 to 3.5 and it brought my PH reading from 7.8 to 7.2 or 7.3. I am testing with the TFT100 test kit. My water is now VERY clear and I love it so I didn't really need to shock it. I am trying to bring my PH back up to 7.6 now by running our sheer descent. We have had a lot of kids swimming in the pool this past week and so maybe I just needed a chlorine boost and a little more run time. However, I can't figure out why our salt ppm is fluctuating like it is. Any help or suggestions? I bought some Morton All Natural Solar Salt last night and was ready to put 80-120 lbs in this morning but then I noticed the light went off and I tested it again, and like it said it went from 2800ppm to 3200ppm in one day. HMMMM?????
 
So should I add some salt just to be safe or just leave it be? I have about a 24k gallon pool. Also, how accurate is the CYA and CH test on the TF100 Test Kit? I am showing that it is testing at about 130 for CH and only 20 for CYA. However, my start-up guy said that I should not be anywhere near that low on the CYA because he added 9 lbs at start-up and it was reading 50 then. It's only been about a month. He also said that we have hard water here so I shouldn't need to add Calcium Hardness Increaser (still not sure if I can use Ice Melt from Home Depot or not) to my pool. But like I said, it is reading at about 130 to 150.
 
I might bump it up a 200ppm or so just so it does not shut off.

The CYA should be good to +-15ppm I think. Who tested the 50ppm level?

Your CH does seem a little low and would be safer for the plaster to add ~100ppm. It will go up due to evaporation, but that is going to take awhile.
 
Because it is early in the swim season it is best to start with the salt level a little high. The salt level will tend to go down over the course of the season, as water gets plashed out, backwashed, overflowed, etc. By starting a little high now, you will hopefully end the season still above the low end.
 
I might bump it up a 200ppm or so just so it does not shut off.

The CYA should be good to +-15ppm I think. Who tested the 50ppm level?

Your CH does seem a little low and would be safer for the plaster to add ~100ppm. It will go up due to evaporation, but that is going to take awhile.

My start-up guy tested it. Should I not be able to see the black dot AT ALL for the CYA test? If so, we are down to the 20s.
 
He tested it with my tf100 test kit. If it went from 50-20 in a month or two, could I have a leak or something? I'm not losing a lot of water though. Or maybe he just test it wrong. He put in 9 lbs to start-up. Would that be enough for a 24K gallon pool? Does it matter what brand of CYA I get? That stuff as well as the Calcium Hardness increaser is expensive stuff!
 
Would that be enough for a 24K gallon pool?
Use PoolMath above to calculate that. You will use PoolMath for many things so now is a good time to start.

While the CYA test has a lot of leeway, it is pretty dependable and if it says you have twenty ppm, that's pretty close to what you have.

It is not uncommon for someone new to the tests to have variances. Stick with it and do them carefully but, time after time, those tests in the TF-100 prove themselves to be accurate.

Don't depend on the pool guy to test it for you.....do your own testing and trust the reults.

PS - leave your pH alone.....it'll start to rise naturally.
 

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