This project was designed to study the effectiveness of using plants and household materials to remove toxins and waste from aquarium water. Aquarium water was cycled through gravel to remove solids, and then through a chamber which housed nitrifying bacteria. These bacteria converted the aquarium waste products, such as urea and ammonia, into nitrate molecules, which plants can use as nutrients. After being passed over the roots of the plants, the water is then returned to the aquarium, cleansed of toxins. The system ran for just under one year, and produced nine cucumber vines, each approximately 4 feet in length. All goldfish involved continued to live long after the experiment’s conclusion, and as of writing this in 2017, many of them are still alive today.

All of the goldfish in this project have been hand fed since a young age. As a result, they are very well acquainted with the presence of (well-washed) hands in their tank. They often school around any hands in their water, play with them, and look for something to eat.

The plants float on a raft, with their roots suspended in open water. Bubble stones underneath the water oxygenate the roots while they absorb nitrates from the water.