If you haven't seen them, check them out, soda can solar heater. I haven't built one yet but will for sure in the future. Suppose you used solar heaters in a greenhouse what would keep your temperature through the night in the winter? Winter, green house, freezing and aquaponics I must be crazy!
My real goal is to have a fish house that would be kept at a nice warm temperature. This fish water would be pumped out to unheated hoop houses and returned to the fish house. Most likely two hoop houses. One mini hoop house over a raft style growbed(s) and a larger tradional hoop house over all of that. Some members already have this style of growing going but just not in a winter/snowy area. Yes, at times I am very jealous of the aquaponis in Florida and Hawaii or anyone else with a nice mild growing climate. Beyond that I believe I can and will accomplish winter greenhouse aquaponics close to or 100% green energy.
Any thoughts or wisdom...