DESC: MicroBIOFALLS creates a perfect base for building beautiful, leak-free waterfalls. Requires only once a year cleaning when used in combination with a skimmer pre-filter. Non-clogging design allows even distribution of water aiding filtration. BIOFALLS can be sunk into the ground for a stream effect or raised to create a greater water drop. Media Net Holds up to 30 lbs of Lava Rock, Manufacturer: Aquascape