My pool came with a simple blue SWG. It worked pretty well for the first year, ever since then, the cell and flow sensor have been replaced. Fast forward three years later and now the system has stopped producing chlorine. I am looking at replacing with a pentair IC20. The pool is an inground vinyl liner 11K gallons. Anyone have any thoughts if I need to go to the IC40, or if you recommend I go with a different system due to horror stories?