Sweet Water Organics
Milwaukee, Wisconsin

Scope of operation        
Focus on perch cultivation & produce for local market
System mimics wetland: gravel & variety of plants filter water; plants are nourished through fish waste in water supply

Facilities
Empty industrial / manufacturing building

Products
Tilapia, perch (local native fish / popular for fish fries)
Vegetables: lettuce, basil, tomatoes, chile peppers, watercress
(had raised 3,000 perch / 45,000 tilapia at time of article; intend to focus on perch)
Vegetables are more profitable than fish – but having both in system increases efficiency

Inputs
Compost (from local restaurants that are supplied by Sweet Water)
Fish food
Electricity (light, pumps)

Waste
Solid waste from fish (must be removed from system periodically)

Additional benefits
Occupy unused urban space / infrastructure (abandoned manufacturing sites)
Reduce farm-to-table distance
Reduce water usage & soil disturbance
Bring native fish back to local diets after perch fishery collapse
Provide contaminant-free fish & produce in polluted areas
Reduce food production footprint

Potentials for increased efficiency
Include vermiculture to convert fish waste to plant nutrients
Explore alternative energy sources (wind, solar)
Reduce energy usage (daylighting plants, gravity-based water circulation systems)
Expand operations to include aquaculture system training & installation
Add rooftop farming operations to decrease urban impervious surfaces

Natural Green Farm
Racine, Wisconsin

Scope of operation        
Focus on plant production / fish is additional benefit
Growing system made up of fish tanks topped by hydroponic growing trays; feeder tubes drip fish water into hydroponic system/ plant wastewater drips into fish tanks

Facilities
10,000SF of 200,000SF factory building

Products
Lettuce (currently 7,000 heads)
Fish (24,000 tilapia / varying stages of development)
Goal: 4 million heads lettuce, 1 million pounds fish, rooftop tomato greenhouse

Inputs
Electricity: grow lights ($0.40 / head of lettuce)
Electricity: water pumps
Fish food

Savings
Water (<10% of traditional agriculture usage)
Space (vertical stacking)
Pesticides & fertilizer (none used)

Waste
Solid waste from fish (must be removed from system periodically)

Additional benefits
Occupy unused urban space / infrastructure (abandoned manufacturing sites)
Reduce farm-to-table distance
Reduce water usage & soil disturbance
Reduce overfishing
Provide contaminant-free fish & produce in polluted areas
Reduce food production footprint

Potentials for increased efficiency
Include vermiculture to convert fish waste to plant nutrients
Include composting to augment plant nutrients
Explore alternative energy sources (wind, solar)
Reduce energy usage (daylighting plants, gravity-based water circulation systems)

EDUCATIONAL SCALE OPERATIONS

Mt. Gravatt High School, Brisbane, Queensland, Australia

Fish and crustaceans in two tanks are fed standard fish feed.  Their natural wastes [feces, urine, uneaten fish feed, plus minute natural water plants and animals – algae and microbes] are then converted into plant food by the water’s living organisms.  Vegetable and fruit plans are fed only these nutrients.

Cost: $4,000 plus donated construction labor
Main elements:

• Two lockable rooms [3mx6m] constructed of wire mesh, shade cloth and plastic roof sheeting
• Two second-hand tanks – one for 25-30 barramundi fish and one for 40 redclaw crustaceans
• Two old bathtubs filled with crushed rock, along with two purpose-built fiberglass grow beds
• Piping to connect the fish and crustacean tanks with the vegetable growing bath tubs and grow beds
• Two pumps and filters
• Tools