Undergravel filters use the gravel itself as a filter medium, drawing water down through the gravel bed and collecting wastes and debris in an open space underneath. Powered by an air pump, they’re a great way to add extra biofiltration and aeration to your Garden, Fountain or any aquarium.
We recommend supplemental aeration or mechanical filtration for tanks with more than 4-5 small fish. If you don’t use an undergravel filter, it’s a good idea to periodically agitate the aquarium gravel or use a “gravel vacuum” siphon to remove trapped wastes. Check out this blog article for more information!
