Several people were interested in our greenhouse project here at Sunny Oaks. We are building an aquaponics system to grow fruits and vegetables for our own use and to start a CSA as well as sell to restaurants and farmers markets. Aquaponics is a nearly self-sustaining closed system of an aquaculture (fish farming) and hydroponics (plants grown in water). The waste from the fish is delivered to grow beds filled with a media such as expanded shale instead of soil. Bacteria, the good kind, grows on the media and breaks down the fish waste into nitrates. Worms are then added to aid in the breakdown of organic matter.
There are some great youtube channels/videos that describe these systems and how they are built:
Citizen Peng - https://www.youtube.com/channel/UC5zfNTsLJItgpETSWWMstVg
Bright Agrotech - https://www.youtube.com/user/BrightAgrotechLLC
Bigelow Farms - https://www.youtube.com/user/web4deb
RobBob - https://www.youtube.com/user/bnbob01
Pratical Aquaponics - https://www.youtube.com/user/MurrayPonics
Phase 1 of the build is the greenhouse foundation and a lost cost cooling method known as earth tubes. This cooling system should allow us to have a longer growing season during the warmer months. Earth tubes is a concept first developed and used by the Romans and is just now starting to make a comeback. The idea is to circulate the hot air in the structure through tubes in the earth. The soil acts as a heat exchange, taking the heat from the air which reduces the temperature of the air. When the air comes back into the structure at the cooler temperature, the overall temperature in the structure is reduced. The earth tube system is effectively an air conditioner only using a fan and buried “tubes”. These tubes are typically a corrugated drain pipe. There is surprisingly little research on these systems. The information on how to construct them comes from empirical data and rules of thumb collected from the practical experience that people have documented on the web.