I have an IC20 that I just replaced the flow switch on, after noticing my flow indicator light was red. Now on the SWG the flow light is green and so is the cell light, however, the salt light is not on at all. When I run the diagnostic test, it shows that I have ran the cell at 4k hours and the salt light is red, but other than running a diagnostic on the SWG, the salt light will not come on at all. I have done a salt strip test on my water and it shows that the pool is at about 3700ppm. What could be the problem?