Salt level rising?

[ultimate_ed]

A couple of weeks ago after my builder finished repairs and refilled the pool, he added bags of salt and left two more for me to add later. After a few days, the reading on the IC-40 was showing only 2300, so I added the other two bags. After several more days, it settled at 2600. This was consistent with what I had seen during the first fill up - one 40lb bag raised by level by about 150.

So, I picked up four bags, but only added three of them. After several more days, the reading settled at 3350, which was higher than I expected, but looked good enough that I never added the fourth bag.

After about a week at 3350, it started reading 3600 and this morning it is showing 3800.

Since I finished salting, I've added two gallons of liquid stabilizer and four lbs of dry CYA as I've been working to bring my CYA up from its initial zero state. I added one 168oz bottle of clorox to help get the chlorine level up while the generator was seeing low salt. Finally, I've put probably 8 gallons of 31.45% muratic acid as I've been working to bring my pH and TA down.

According to the calculator, it should have taken an additional 102 lbs of salt to take me from 3350 to 3800. So, I'm having trouble figuring out what is driving the reading up. I've had a few inches of evaporation, though I'm still above the skimmer levels and I've been holding off on adding any more fill water as the pH and TA of the fill water are quite high. I wanted to get the levels down in the initial fill before I started the process again by adding more water.

So far, I've been relying on the reading from the Easytouch panel for the salt level.

I'd appreciate any suggestions as to what I'm seeing here.

 

[dmanb2b]

Both Chlorine and muratic acid add salt as a byproduct to water, but not to that extent. Has there been any significant change in water temp between those readings?

 

[Boland01]

Make sure your SWG is good too. As they start to fail or if you have a large build up of calcium on them they can give you erratic readings. I usually add half a bag then wait 30 minutes and add more. Gives the salt time to dissolve plus I don't get the "high amps" reading on my control board.

 

[ultimate_ed]

That certainly wouldn't be good as the SWG is about 3 months old. As for temperature, had been running around 85/86 before and now its down to about 80/81F.

I went ahead and ran my numbers to see if they would offer any insight:

CYA 32 (about what I expected, I've got another 4lbs of CYA to add, but I wanted to see what this first reading came to after what I initially put in)

TA 150 - still got a long way to go on this one. Put about 8 gallons of acid so far. I've got another 2.5 that I can add before another run to the store.

pH - 7.5 - Started out at 8.4+ along with the high TA reading. After my latest gallon of acid, I had expected to be down to 7.2 this morning.

CH - 250

FC - 8

CC - 0

I guess I'll see about getting a salt testing kit to see what kind of reading it gives me.

 

[Boland01]

Cooler temperatures can change the reading too. More than likely that is what's going on unless you've lost alot of water. I've got a 28.000 gallon pool and if the water level drops (or rises) by a couple inches the reading will change by a 100 to 200 ppm. Nothing like what you are seeing though.

 

[phipsi1237]

If I remember correctly, the swg should be turned off when adding salt.