I bought a $25 milk house heater to heat my GH... I had the thermometers below heater level and since heat rises, it was basically measuring a bit higher than the outside air temperature. At 35F it keeps the GH at about 50F, but only above the heater level which is on the top shelf... So the pots that my Nepenthes are in are getting 40s and the plants are getting 50s at night. I would move the heater down a shelf, but then it wouldn't heat as much and if water got dripped on it from plants above, I don't have a heater anymore.

So which matters more to keep warm, the roots or the leaves? Also, does anyone have a recommendation for an actual good heater that can heat really well? I guess $50 is like the limit of what I want to pay... Do you think an oil heater would be the best? I saw one at Home Depot and someone told me that it just heats the oil and it is much more effective. So is that the way I should go?

It gets 25F at the lowest on a cold winter night, usually around 35F-40F on winter nights. I don't need a heater during the summer, it is just for winter. The GH has heat loss issues but it is the material it is made out of, I taped up all the cracks that I could find and I plan to do even more taping.

Thanks in advance!