Greenery above

Floating plants thrive in opentopped tanks and provide an upper canopy of greenery that offers a perfect habitat for surface-dwelling fish such as Guppies. You’ll also see many plants producing flowers — not just the obvious things like water lilies, but also the lovely purple flowers of Hygrophila and the floral spikes of Aponogeton. Sometimes these flowers produce seeds, and Aponogeton crispus, for example, is self-fertile and the seeds it produces readily germinate in the aquarium. Houseplants positioned nearby can be allowed to trail into the aquarium, with the Pothos plant, Epipremnum aureum, being a classic choice, sending roots into the water and sucking up surplus nitrate.