Hnotskurn: Aquaponics is the cultivation of plants and aquatic animals in a recirculating environment. This ecosystem utilizes natural bacterial cycles to convert fish waste to plant nutrition. In the project, species from the fungus phylum will be added to the cycle. Growth and efficiency of two varieties of oyster mushrooms will be measured in goldfish aquaponics systems at Ísponica in Hólar. For this study, the mushrooms will serve as an extra water filter after the vegetable (lettuce) grow area. Because mushrooms are unlikely to filter all the nutrients from the water as effectively as lettuce, additional aquaponic setups will be built using only mushrooms and no lettuce to see how well the mushrooms utilize extra nutrients in the water. The effects of water quality on mushroom growth and nutritional content will be analyzed. Growing plants and mushrooms in combination using aquaculture waste will increase the sustainability and efficiency of food production here in Iceland and abroad.