Remember SWG dont run a % of power. They always run at 100% power for the fraction of the time selected of 1 hour. So if you are running 50% then its ON at 100% for 30 minutes of the hour. So what i do is run it 100% setting for only the amount of time needed to produce 3-4 ppm. If your water is not skimmed with that much time then run the pump the extra time needed with the swg off. This is if you have automation, if not then you can play with SWG settings.