Hi guys, I’m a new hot tub owner (came with the house): Life’s Great model Sanctuary 2015. 4 seater. About 15 of our jets are broken but the spa motor and heater are functional. It is winter, low of -10 C have started. We have used our spa couple of times and never had to fill the spa until we decided to keep the temperature steady at 104 F. Overtime (2 weeks) the water dropped below the filter line (2-3” below normal levels) It is worth mentioning that tub cover, does not seem very adequate, it doesn’t seem to seal properly.
Now my question is, considering the colder weather, maintaining water temp at 104 along with an improper hot tub cover, is it possible that water evaporated 2-3” below normal level?