I am planing a 12x12 greenhouse because its the biggest I can build in my area w/out a permit
next to it I am digging a ~1200gal pond, this will be between my existing garden beds and the greenhouse.. I am going to have the pond actually come inside the greenhouse slightly, I was thinking a tunnel made of cinder blocks... This will give fish a hiding spot indoors from predators, allow me to pump water in/out of the pond from inside the greenhouse and keep the inside portion ice-free in winter.. Were going to have to go 4ft or deeper to keep it from freezing solid here. Where the pond comes into the greenhouse will probably be covered in grating and all the pond equipment will be under a raised plant bed as to not take up too much floor space.
Inside the greenhouse I was going to do a few large ebb/flow hydroponic trays filling and draining from the pond, dosing using aquarium nutrients so its safe for the fish.. A 100lb propane tank with a heater so I can start my garden in April.. my goal is to make the greenhouse and pond solar powered, running pumps, filters, fans all off batteries and solar panels.
On the other side of the greenhouse from the pond ingress I was going to dig a small root cellar deep enough to store bulbs over the winter... Were not planning on heating it all winter, just early spring and late fall as needed with a thermostat.
I am demolishing a shed in the area this summer and preparing to start on the greenhouse first.. I am at best a few years out from seeing my plans completed... Ive got concerns over snow loading so will probably build mine a very steep roof