Also has low salt message….. I have cleaned the cell and does not help…. From what I have read the T-Cell-15 needs to be replaced, but I want to be relatively sure that is the problem before I buy a new one. The message came up while I was out of town for several days. The CL check .5 by then. I did a "SHOCK TREATMENT" yesterday to keep the pool clean until I figure out what's going on. Any other possible problems with the system other than the cell? Thanks in advance for your assistance.