Food is just one of those things that we need to survive. Plants can grow on their own without human intervention but the quantity and quality of the crop will vary from year to year. Even elaborate farms can have good and bad years due to variables such as weather, disease, bugs, pollution and soil condition.
There is a system called Aquaponics that attempts to control those variables. Aquaponics combines aquaculture (raising aquatic animals) with hydroponics (growing plants in water). The Aquaponic system tries to emulate what happens in nature without the variation; water-based animals eat plants and excrete waste and that waste is used as food for plants.
[Kijani Grows] has built an Aquaponic setup and added a smart controller that is made out a bunch of stuff you would not normally associate with a garden. Their are several sensors in the system that measure water flow, tank level, water quality and dissolved oxygen. An Arduino monitors these sensors and reports the information back to a $20 router running OpenWRT. All of the recorded data is also stored for review later. Software on the router determines what needs to be adjusted in the enclosed ecosystem. The router communicates this information back to the Arduino which in turn controls the water pumps, heaters, fish feeder and lighting. And as if that wasn’t enough, the control system can be set up to send out messages via email, SMS or social media.
This is some extreme gardening. [I Am Become Derpth] didn’t let lack of space or tillable soil stop him from growing a bountiful harvest. Instead of cutting though prairie sod to begin the farming he had to contend with the concrete expanses found in the NYC area. Here he’s nearing the end of an impressive aquaponics installation in Brooklyn, New York.
For a good overview of what aquaponics is all about we suggest you take a look at this Oakland, CA setup. The heart of the system is a closed loop that uses both plants and fish for balance. The byproduct is edible greens. The image above shows the growing beds through which water is circulated. They’re filled with clean gravel which keeps the roots happy. Once the water has made it through this system it is piped into the basement of the apartment where water tanks filled with fish reside. The system uses the fish waste (broken down by bacteria) to feed the plants.
It’s an efficient system but one thing’s for sure, you don’t just go out and buy a rig this complicated. We think you’ll really enjoy going through the build log linked at the top.
[Eric Maundu] is farming in Oakland. There are no open fields in this concrete jungle, and even if there were the soil in his part of town is contaminated and not a suitable place in which to grow food. But he’s not using farming methods of old. In fact farmers of a century ago wouldn’t recognize anything he’s doing. His technique uses fish, circulated water, and gravel to grow vegetables in whatever space he can find; a farming method called aquaponics.
The video after the break gives an excellent look at his farm. The two main parts of the system are a large water trough where fish live, and a raised bed of gravel where the fish waste in the water is filtered out and composted by bacteria to becomes food for the vegetables. More parts can be added into the mix. For instance, once the water has been filtered by the stone bed it can be gravity fed into another vessel which is being used to grow lettuce suspended by floating foam board. But the water always ends up back in the fish trough where it can be reused. This ends up saving anywhere from 90-98% of the water used in normal farming.
But [Eric] is also interested in adding some automation. About seven minutes into the video we get a look at the control systems he’s working on with the help of Arduino and other hardware.
Continue reading “Urban farming uses aquaponics to make farmland where there is none”