Duo works on a very nifty principle. Symbiosis. That’s when two organisms or types of organisms live off one other, supporting each other. The Duo is an aquarium/planter that keeps fish healthy, while also using the waste eliminated by the fish to feed the plants. The oxygen eliminated by the plant then goes on to oxygenate the water the fish lives in. This beautiful cycle keeps both fish and plant healthy. What a beautiful design for a co-existence habitat! Designer: