Northern Liberties: Gardening with Fish

Brent Boyd with his girlfriend, Liana Dragoman, tending to the aquagarden

It’s the end of spring and heading toward summer. All of the plants are coming into bloom. Everywhere you can see small and large urban gardens throughout the city. All plant life seems to be blooming in green and various bright, brilliant colors. Many of the gardens are a

Brent shows us one of his sources for plant fertilization, a crayfish

pleasing sight to the eye, yet, at times, can be somewhat ordinary.

But one local Northern Liberties resident makes quite an impression when it comes to his urban plot. In an area of about six feet by 30, making up less than 180 square feet of land, sits Brent Boyd’s aqua-culture garden. “Being here in the city, I only have a small area in which to work. So, I tried to scale it down where we could make the best of our limited capacity.”

Brent Boyd with his girlfriend, Liana Dragoman, tending to the aqua garden

Despite the tight vicinity, Boyd, a doctoral student at Drexel University in enginering, has managed to make the space work. The aqua garden not only flourishes in true beauty, but also provides food for Boyd and his girlfriend, Liana Dragoman, plus, the plants, goldfish, crayfish and earthworms.

Boyd says the point of this setup is to deposit food waste in the garden, eventually giving back even more food later. So, how does waste become food? Boyd dumps his leftovers from meals in a large tank housing goldfish and crayfish. The purpose of these creatures is to consume the waste (and from what Boyd says, make a tasty meal at the end of the season) and produce their own waste in the form of ammonia. The ammonia-filled water is carried through pipes into a bio-filter. Bacteria living within the bio-filter convert the ammonia into nitrates. These are pure nutrients for plants. Nitrates are pumped onto a hydroponics table, where the plants grow. Hydroponics tables are essentially shelves flooded with water where the plants mature. Boyd makes sure to rotate the plants on his two-tiered hydroponics system every few days to make sure they all get their fair share of sunlight.

Boyd tends the crayfish and goldfish.

As for the earthworms, they are given scraps from fruit and vegetables as their food source. They eventually breakdown the waste into rich, healthy soil on which the plants thrive.

The system may sound slightly complicated, nonetheless, Boyd says it’s simply an experimental endeavor that seems to be going quite well so far. All life forms within the aqua garden seem to be gathering waste, using it as a source for food, and depositing waste to another. It appears to be one of the ultimate forms of home-based recycling, or in other words, a small urban ecosystem.


  1. Brent,
    We met at tht TEDX conference in Phoenixville last year. We were eating lunch at the same table when you spoke about your hydroponic garden. I was wondering what you were up to this year?
    I had a greenhouse (8×23) built on the side of our house last December and would like to start growing vegetables using hydroponics. This would be my first attempt and I’m not sure where to start. I live in North Coventry Township just outside of Pottstown and I can be reached by e-mail at
    Carl Landis

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