Well, night temps seemed to fall like norm with the floor sealed to the GH. But day temps are now much higher, in the 90s when it was just in the 40-50s before.
Your GH and shelving looks GREAT! Good job. I think the plastic on the floor is a very good idea, too. Any air leaks during cold weather can lower the temperature in there considerably. The air leakage also has a tendency to drag the moisture in the GH air down. It is good to keep the humidity high in all greenhouses to reduce evaporization of your watered plants. It looks to me like you're on your way to a great growing season.
Set up the electric heater and will chance it. We'll see if it can keep it warm or not tonight. If so, I'll move the little plants, pond plants and ducklings in there. Will be nice to not have all those plants taking up so much space!
Heater is on.
6:30pm. 55F outside, 60F in GH.
Heater is on low for now, I'll go out and turn it up if the temp in there gets under 50. And keep turning it up if temp keeps dropping, up until it's on max. Hoping it won't need to be on high though.
I'll have to use another thermometer tomorrow in the GH to see if it's reading the right temps. The thermometer on the porch is about the same as the weather station, GH one is always lower...I don't get how it can be colder in the GH than the air outside it...
Also don't get how the battery can already be low...