Here is a image of our aqua zone in our eco-column. we used river water so that it would already have sufficient nutrients to sustain life forms. we also place some simple pond weed in this zone but sadly it will not last very long as the water is not being oxygenated and this plant relies on oxygenated water. if we wanted to oxygenate the water we would either have to install a pump or find some way of keeping the water moving. we also have water snails in our aqua zone but they will also die due to the lack of oxygen in the water.