Salt readings low to high

[ping]

I have a 16 month old aquapure and my readings have always been higher on my aquapure than my aqua chek strips. My aquapure measures 3500ppm and my old strips measured 3000ppm. I just ran out of my old strips and the new ones measure 2700ppm. I ran the new and last old test strip at the same time to compare the readings and I got the 300 difference. I wouldn't be too worried about 300 difference between the two strips, but 2700ppm to 3500ppm is a large difference and is at the opposite ends of the operating range. Jandy actually want 3000-3500ppm. For what's worth, the pool store was always within 100ppm of my old test strips and they did not use strips to test.

My sensor went bad a month ago and was replaced under warranty. The new sensor matched what the old sensor was reading before it died. The system is generating chlorine and operating normally.

Do you guys think that the sensor reading is higher than my strips due to the borates in the water? What else would account for that much difference in the readings? Do you think that the new bottle of test strips might be "defective"?

For now I will leave it all alone since everything seems to be working fine. I have no idea what would have caused the other sensor to go bad and neither did the tech.

 

[JasonLion]

First off, none of the salt testing approaches are really better than +-400, and some of them are worse than that. I suspect that the AquaChek strips (which agree with each other within the precision of the test) are right and the SWG is reading high, though it could be the other way around.

There are several people who have had problems with test strips before. And many many people have had problems with pool store salt testing. SWG salt measurements tend to read low when there is a problem. It is rare for a SWG to read high, but that does happen now and then.

I agree with your summation, leave it alone as long as everything is working.