My Chlorine has been low for a couple days. I have a 25000 gal inground pool with a Hayward AquaRite saltwater chlorine generator. The lights say on and generating and do not indicate any problems. My water is clear. My salt level has stayed at 3000 or 3100. I had the person that works on my pool some check that it's set to the right cell size T-15. Hayward says it must be a chemical problem and to check phosphates and nitrates. The ph is 7.5, but chlorine has stayed at .5 I don't know what to do. I have the TF 100 testing kit, but I don't think it can test for those. I have been unable to get my water to a pool store as I am an assistant principal and this is the first week back to school- the stores close before I get done. The water still looks great now, but I know it won't stay that way if the CL stays low. Any suggestions would be great!