Look into Chinese greenhouses. There are the best for aquaponics with their insulation properties. Also, rather than try and heat and cool the air, heat and cool the water. The water is your biggest biomass. Water very, very slowly absorbs or loses heat while the air loses heat quickly as there is no biomass. A solar water heater and heat exchange is perfect to keep the water at temperature even when it is extremely cold outside. To cool the water, trenches can be dug and geothermal lines installed that will be used with the heat exchanger to cool the water in the summer. Insulate your tanks and grow beds well so that the water continues to hold heat/cold longer.
I'm in AZ and about to start my own aquaponics so I've done a lot of research on how to accomplish a thriving system in our brutal environment. I will be building a Chinese greenhouse and using the above ideas as well. Good luck with your system.
