Circulation pumps simulates natural river and reef currents by continuously circulating water. Efficient and easy to use. For use in 100-gallon aquariums. Whisper air pumps can handle the aeration needs of aquariums from 10 to 100 gallons. Works efficiently in higher head height applications. Heavy-duty construction provides strength and corrosion resistance. Ideal for use in skimmer filters and pondless waterfall applications.