Here is a picture from last winter inside the greenhouse. It was cold out early in the season last winter but things were still moderate enough inside the greenhouse to keep the tropical plants alive at least early in the season. This winter is different with no protection from the cold. We have already had a few freeze nights this year and all the tropical plants are done in.
Even though it got cold and the fish have slowed down eating a big, the weather warmed back up and the fish are eating again though not as much as during the warmer seasons.
I actually think having my system exposed is giving me better production on things like lettuce and other cool weather crops. In past years I would have tomatoes surviving into the cold season and getting attacked by spider mites in the greenhouse as it got cold. This year the tomatoes are gone sooner and I’ve re-planted with broccoli, cabbage, kale, collards, beets, turnips, radishes, and of course lots of lettuces.
Our warm season is plenty long that I don’t need to nurse tomatoes through the winter. Also it isn’t as if the greenhouse really kept things warm enough at night to make any of the warm weather plants happy and the fact that the greenhouse would still get really hot during the day when it was sunny meant that the cool season crops were not doing very well either so I’m probably better off without it.