AQUAPONiCS:

As part of sustainability and Edible Campus initiatives at the University of New England, a student-centered aquaponics system was developed. Aquaponics is the fusion of two sustainable practices, hydroponics and aquaculture, in which the waste of one organism is beneficial to another. Hydroponics is a soilless, growing plants in soil-alternative media or fully immersed in water.

In comparison to aquaculture, which prioritizes fish as the end product, aquaponics prioritizes plant production with marginal emphasis given to fish productions. Similar to recirculating aquaculture systems, aquaponics relies upon efficient hydrodynamics and system engineering for concentrating, collecting, and removing waste.

Solid waste from fish and uneaten food are mechanically concentrated and collected for use as fertilizer in the campus garden. Soluble nitrogenous waste is handled by the a biofilter where the process of nitrification occurs via bacteria that convert toxic ammonia into soluble nitrate and nitrite that nourish the plants in the gutter system and grow beds. The plants filter the balance of chemicals and nutrients, purifying the water and rendering it safe for the fish resulting in a natural, self-sustaining, symbiotic ecosystem that guarantees some fresh fish and lots of plants and vegetables.

The multiple iterations of this project were a great example of how small, but concrete steps contribute to progress and help advance a vision. The success demonstrated by this prototype system helped justify additional and substantial investments. The facility is currently awaiting the installation of scaffolding that will allow the project to grow upwards, thereby creating a living wall that will become a centerpiece exhibit and a major crop producer for the Edible Campus initiative.

Edible Campus: The goal of the Edible Campus initiative is to intentionally produce food products that could be supplied to campus food services or sold by entrepreneurial ventures within the university. Aquaponics seedlings are started early indoors and are supplied to the campus gardens throughout the outdoor growing season. Solid waste collected from the aquaponics system are solubilized and used as natural fertilizer for the gardens.

Featured

v2.0 Rainbow Trout and Basil

Our proof of concept earned us some experimental space for a larger system and access to the equipment 'bone yard' for repurposed supplies.

v2.0 Complete

Form left to right, the trout holding tank, plant bed, biofilter, and tenacious intern Mr. J.

v2.1 - Ideas evolve

The addition of homemade LED lighting and a floating raft system.

Here come the trout!

Lettuce and Basil Seedlings

Sharing ideas

Maine's very own Tyler Gaudette of Fluid Farms spends an evening with us talking hydroponics and entrepreneurship. He also shared lessons on system simplicity and gave us advice about running our own system.

v3.0 Better Hydrodynamics

After holding trout for several weeks, we quickly learned that our original tank system did not flush solids very well. Taking notes from our Aquaculture Engineering experience, we built a new tank with improved self cleaning features.

v3.0 - Radial Flow Filtration

Solids from the new self cleaning tank are sent to the radial flow filter, a mechanical device that capitalizes on water's tendency to seek its own level and counter current resulting in a system that concentrates solids at the bottom and supplies 'clean' water to the biofilter from the top.

v3.0 - Red and Blue LEDs

Our original DIY LED lighting proof of concept earned us some funding to invest in blue and red LED's. Blue light helps give the plants strong, healthy stems and leaves. Red light is responsible for making plants flower, produce fruit, and grow roots. We also incorporated an adjustable height fixture design that helped control light intensity.

V3.0 Biofilter

The biofilter was repositioned in-between the radial flow filter and the grow bed helping capitalize on gravity flow and simplifying system operations.

Happy Lettuce

The efforts that went into v3.0 paid off with a simplified system of fewer moving parts, improved flow, and happy lettuce and fish.

v3.1 Gutter System

As we began to understand how to manipulate and predict system water quality, we realized that we had a nutrient surplus and could raise more plants. The addition of a gutter system allowed us to go vertical and horizontal in the same footprint.

v3.2 A long way from goldfish and a boat battery

(From L to R) The newly designed and simplified system consisted of a self-cleaning trout tank, a radial flow filter, biofilter, gutter system and floating raft system. The system required only a single pump and in the event of power failure all of the components would retain their water. Other components included a single air pump and a water chiller that was used seasonally.

The intense purple coloration results from a combination of red and blue LEDs.

V3.3 Mineralization

Mineralization tanks (tall cylinders, far right) were added to further process the solids captured by the radial flow filter. The mineralization process uses aeration to mechanically tumble solids in the presence of oxygen, turning the solids into bio-available nutrients that are reintroduced into the system in lieu off-the-shelf supplements.

Mr. T. showing off the fruits of his labor. Note the prolific root growth.

v4.0 Scaling up!

Some brainstorming about space maximization in preparation for scaffolding for the living wall.