I will close my pool in 2 weeks in update NY. According to TFP I bring it up to slam levels. To clarify what should FC be at closing? Slam or regular level. I have a 13500 salt water pool and a First time pool owner. Our water was crystal clear all season (used all the Taylor tests). Do I have to add Polyquat, I never had any algae? Planning on waiting until water is 60. Also what about those "wintering balls" are they helpful or bad? Any other chemicals needed??