Extremely High Salt Reading on Aqua-Rite 940 system

[Tyrone Shuz]

19k gallon vinyl SWG pool; Pentair DE 3.6, 1.5hp pump

I was getting low salt readings the day after I started the nearly-new SWG system (installed last July). Before I started I removed the cell and cleaned it (it didn't need it, it looked brand new but I still gently used cable ties and poked through each grate opening). Anyway it was around 2700 and the next day it was 2100. I bought 4 bags of salt, put a couple in, and it went up to 2600--put the other two in and now it reads 6700. I tried the recalibration thing with the switch but the reading recalibrates to the same spot.

My silver nitrate drop test has me around 3200-3400, a strip gave me around the same. What do I do? Last summer the tests and the unit were always at least within shouting distance of each other.

 

[JamesW]

What are all of the diagnostic readings?

Is any salt being sucked into the main drains?

 

[Tyrone Shuz]

Yes my main drain is on. I usually use skimmer only once the pool is cleaned up. But I don't see how the water coming through the main drain is different than the skimmer if the salt has dissolved properly. I'll have the diagnostic readings when I get a moment.

 

[JamesW]

But I don't see how the water coming through the main drain is different than the skimmer if the salt has dissolved properly.

You need to be 100% sure that all salt is dissolved.

Brush the pool thoroughly 3 X.

 

[Tyrone Shuz]

DIAGNOSTICS--6700, temp=64, 27.3, 4.38, 69% (I run around 41% when up and running) -6300, AL-0, r1.59, t-3

 

[JamesW]

Change T-3 to T-15.

 

[JamesW]

If your settings are changing randomly, you should reset the display board.

 

[Tyrone Shuz]

I changed the tCell to t-15 and the instant salt now reads -2500. This is my first time opening with a SWG. The salt stays in the pool but with plenty of rainwater (mesh cover) I knew I'd have to add salt. I have put 4 bags in, 19k gallon pool. What is a typical amount with a mesh cover?

 

[JamesW]

What is a typical amount with a mesh cover?

You can't really go by "typical".

You need to be 100% sure about the salinity.

Brush the pool 3X thoroughly to be sure the salt is 100% mixed in.

Test the salinity at least 2 new ways that are reliable.

Does the cell say 940 on the label?

 

[Tyrone Shuz]

Yes it's a 940T. I've had the robot do the pool several times. The readings now match at 2500. By that number I need two bags (would bring it to 3100 or so). The Taylor strip test, by my eye reads in the 3000 range. If the machine says 2300 or less it will stop producing chlorine so if they don't agree, I'll believe the strip or drop test (drop test a couple days ago was 3200-3400. I'd believe I'm doing something wrong before the machine failing only because it's so new. But I've read the machine's readings often don't agree with drops or strips. I won't rush off to buy more salt till a few more tests have been done over the next week or so (unless I get more idiot lights on my machine's display).