I have a 22000 gal IG vinyl pool with a SWG. We just installed the SWG this spring and for the most part it's been great. But lately I am having trouble keeping my chlorine level up. I tested the salt level with test strips and my strip said I had 4790ppm of salt. I have an Atlantis SWG and they recommend a level between 4000-5000 ppm. I took a sample to the pool store and they said I had 3780 ppm. My neighbor has an salinity meter and his read 3900 ppm. Which do I believe? I just noticed my salt strips expired 6/2010. Could that make them read high?
Here are my levels yesterday:
CL .5
Alk 90
PH 7.6
CYA 50