Aquaponics is a hybrid of hydroponics (growing plants without soil) and aquaculture (raising fish in contained systems). Aquaponics is an energy-saving and efficient way to grow lots of food in a small amount of space, using biomimicry to engineer a functioning ecosystem in which the wastes of one process become resources for another. Fish waste feeds the plants, and plants clean the water which is returned to the fish tanks. Beneficial bacteria in our filters break down fish waste so that it is easily absorbed by the plant roots, and beneficial insects and organic foliar feeding help control pest populations naturally and safely.
Plant Chicago’s aquaponic farm currently occupies 7,000 sf in the basement of The Plant. Our growing systems were designed and built by our staff and IPRO students from IIT using as many low and no-cost materials as possible. Our goals is to test the limits of implementing large-scale systems on a limited budget so that our farming methods will be financially viable to repeat elsewhere. Our fish and filtration tanks are built from upcycled food-grade IBC totes, donated from a local commercial bakery. We currently have three, three-thousand gallon systems housing approximately 600 fish each, and about 3000 sf of plant grow beds planted intensively with arugula, lettuce, herbs, and other salad greens. The produce is fed to our staff and volunteers and is sold year-round at one of the largest farmer’s markets in the city.
We are testing various lighting systems, and are currently growing under a mix of T-8 fluorescents, donated LED lighting, and induction lights, both stationary and on light-movers. We are testing the efficiency of these various methods for the different salad and herb crops that we currently grow to determine the initial investment price for the lights, life-span of the equipment under commercial production conditions, and where applicable, replacement costs for the bulbs.
The aquaponics farm also houses its own breeding system, where we are learning to naturally breed Nile tilapia to replenish our tanks when our fish become mature enough for harvest. The breeding tank, now in its fourth design iteration, houses two breeding chambers in which our male and female breeders produce between 50 to 200 tilapia each spawn, with an algae cultivation tank for nutrient scrubbing and fish feed production (tilapia are omnivores and benefit from the fresh food to get them into breeding condition). The tank is further filtered by two linked media grow beds where we are experimenting with fruiting plant production: raising strawberries, squash, and tomatoes on an experimental scale.
On the horizon
We are expanding! Plans this year include:
- Building out an additional aquaponics system using materials from a former Plant tenant. The new system will be a 7,000 gallon system using 8, 8ft x 8ft beds.
- Addition of prawns.