Hello everyone. We're supposed to get some below freezing temps in the mid-west this week (low of -12F tomorrow plus a wind chill). I'm a first time hot tub owner and was curious if anything needed to be done for weather that's this cold to prevent any damage. The hot tub has a circ pump that runs 24/7, I have the temp set to 100F, and the cover is in good shape. How cold is too cold? How long can a tub be in extreme weather like this? Should I lower the temp to avoid over-working the heater? What else needs to be done?