I have been chlorinating my pool for the last couple years with an inline Pentair 320 Chlorinator. I have always used 1" pucks until recently i switched to 3" to save money. After a week or so my cholrine level started dropping to eventually non existant. It appeared the 3" pucks were not dissolving.
So I switched back to 1" pucks 3 days ago and it still seems like i can't get my FC above .5. Usually I can get my FC level off the charts using 1" pucks even with the Chlorinator dial turned down to 2. Is there something wrong with it? It fills with water when running as I have taken the lid off after shutting off the pump and there is water that quickly drains after the lid is removed.
How do I troubleshoot this thing? Google searches have left me somewhat empty beyond checking lid o-ring and making sure it fills and drains with water.