We have a 2 month old 12,000 gallon vinyl pool. We have an Aqua Rite SWG and its been great. Our pool has been crystal clear all summer. However, we dont want to close it being her in Atlanta. Our skimmer and pool cleaner is sucking up leaves fine. Right now we filter 4 hours a day. The SWG is reading 3300. At some point when it gets colder, the SWG wont work. What do we do then? Add shock to keep the water clear? When will the SWG not work?