It's been a year since I tested the salt levels in my pool, but last august they were 3800, which is right where I want it for my SWG. I've noticed that it's been flashing lately for high salt and I tested twice today and it came back at 8,000. What would cause that number to rise like that? I didn't add salt. My water levels are consistent so it's like not I have less water in the pool.