Ponds require water movement to maintain a healthy, well-balanced pond or to create an impressive water feature. Moving water can offer benefits to any type of water feature in the form of re-circulation, aeration, and ornamentation. The best way to move water in a pond is by installing a pump. Even if your pond is solely ornamental, a pump will be required to prevent stagnation, inhibit algae growth, inhibit insect pests, and to power a decorative water display. Stagnant water tends to have a distinctive, unpleasant scent, which is generally undesirable for an ornamental pond. Streams, waterfalls, fountains, and spitters all require a pump.