Those of you who frequent our 7th floor space may have noticed that we have a pond, near the window, full of fish. Several years ago the Concordia Greenhouse Project hosted an aquaponics system for research purposes, and goldfish were donated by the community and acquired from various pet shops in Montreal to stock the large 90 gallon tank that fed the aquaponic plant system. After a few years the volunteers maintaining the aquaponics system completed their study and the goldfish were transferred to one of three ponds that are integrated into the 13th floor greenhouse structure.
The original fish eventually passed due old age – they averaged about 10 years old at the time and were about 30 cm long. As they passed away they were replaced to maintain a good number of fish that kept the pond looking more natural. The current fish population of the Concordia Greenhouse Project consists of a combination of rescued goldfish from individuals, re-homed fish from people who couldn’t keep them anymore, offspring from spawnings in the greenhouse pond, and a donation of a koi fish from Dr. Kevin Gould in the Geography, Planning & Environment Department. There are currently a total of eleven fish living in our pond at the moment.
While the motivation for keeping goldfish at the greenhouse was because of research and later, to stock a pond that was already part of the structure, another reason we enjoy keeping them is because plants love getting watered with water from an aquarium or pond. The water is at room temperature or warmer which most house plants appreciate; and the water is full of nitrates from fish waste and the filtration process. Nitrate is fertilizer, and in fish water nitrates are in a low enough concentration that it feeds the plants a little every time we water with it! Not to mention, they bring in students with new and interesting curiosities about the fish, the system, and our space.
Concordia Greenhouse Project 