Pond Clarity
There are over twenty five thousand known varieties of algae, and it can sometimes seem as if all of them are thriving in your pond! Although algae can be a nuisance, it plays a vital role in all aquatic ecosystems. As pond owners, our goal should be to control algae, not eliminate it. There are three basic types of algae found in water gardens. Floating green algae (pea soup), fuzz algae (slick green fuzz found on sides of pond), and filamentous hair algae (string algae). Fuzz algae benefits your pond by providing food for fish, by breaking down waste, and by increasing oxygen levels. It is generally recommended that fuzz algae be left undisturbed, even during your annual pond cleaning.
Controlling Floating Green Algae
Green algae is best controlled with aquatic plants and biological filtration.
- Strive to cover 60-70% of your pond’s surface with plant life. In addition to surface coverage, submerged grasses such as anacharis and hornwort help to keep water clear. Plants help in two ways. Surface leaves block out sunlight that algae must have to survive, and submerged plants starve algae by absorbing nutrients they use to bloom.
- In conjunction with the appropriate amount of aquatic plants, the use of a properly sized bio-filter is essential for pond clarity. The bio-filter houses filter media which serves as a host for the “good bacteria” that help promote water clarity and water quality.
- To completely eliminate green water, use an ultraviolet filter along with plants and a bio-filter. As water passes under the UV light, it disrupts single-cell organisms (i.e. green algae) and kills the cell.
Controlling Filamentous Hair Algae
The notorious hair algae is every pond owner’s nemesis and the most difficult to control. Since most ponds have fish, we recommend two organic products to use simultaneously: Barley Bales, Pellets or Extract and Microbe-Lift. Non-organic products such as Algae Fix and Algaway 5.4 also kill algae and are fish-safe, but must be used with caution. For best results, physically remove as much hair algae as possible first and then use these products on a regular basis.
