The prevention of algae is made much simpler by reducing the amount of nutrients available for algae to feed on. This is accomplished by having a balanced pond and also with proper filtration. Having a well-balanced pond makes it much easier to avoid having algae problems. There are five factors that are necessary to have a balanced eco-system. Removing any one of these items will make it much more difficult to keep a pond with clean, clear water.
Plants have a variety of benefits in and around the pond.
In addition to beautifying the pond and its surrounding area, plants help control algae. They do this by taking nutrients out of the water that algae would normally consume. Also, there are many oxygenating plants that add oxygen to the pond, helping maintain a healthy eco-system. Some plants, such as water lilies, will shade the pond, thus reducing the amount of sunlight available for algae growth. Large fish, especially koi, will eat a tremendous amount of algae.