A friend and I built an aquaponics system in 2012 for his basement.
Aquaponics is a mixture of hydroponics (soil-less agriculture) and fish aquaculture (hence the cat’s laser-like focus). It is a symbiotic process, where the fish’s organic waste fertilizes the plants, and in return are supplied with filtered water. The only system input is fish food.
The two (2) black plastic boxes pictured above used to be one (1) 330 gallon IBC tote, which are usually used to store and transport fluid and other bulk materials. We cut the container about two-thirds of the way up. The larger bottom tank held 40 yellow perch at the beginning – it can support about 80-90 fish. Water from the fish tank is pumped through the black pipe in 10 minute on/off cycles to the grow bed above. An Arduino housed in the blue box to the right controls the pump and also monitors water temperature. We planned on adding sensors to monitor the water chemistry (pH, nitrates, etc.) but never followed through.
The grow bed is media based. In other words, we use a mixture of rocks and expanded clay (the red stuff) to support the plant’s roots and act as a bio-filter to filter the water and convert fish waste (ammonia and nitrites) into plant food (nitrates). The filtered water falls back to fish tank through the PVC pipe (there are several small holes under the rock), which introduces oxygen via percolation and completes the mostly closed-looped cycle. A set of six (6) full spectrum T5 lamps provide the artificial light. The first crop of tomatoes, radishes, pepper, lettuce, and some wicked cucumbers is sprouting in the plastic containers and was planted within the media within a day or two.
Like most makers, the project lost our attention after it was finished. Before the system was disassembled and sold in 5-6 months, some of the crops were about 6-7 feet high!