I noticed a few weeks back that the Nature 2 fusion is not producing chlorine. I was getting the 120 and 121 codes so I went ahead and cleaned the cell, checked the water chemistry, and salt level to rule out any simple fixes and everything checked out. I then proceeded to change the salt cell as well as the chord from the cell to the control box and I am still not getting any chlorine production. There are no error codes displaying now and both "flow" and "cell on" are lit up green. The chlorine levels are raised when I add shock but the levels diminish within a couple of days. Any ideas on what the issue could be or what else I should check?