String Algae Profile

Pond, Green String Algae Control, Removal, and Treatment Paradigm

String Algae is caused by a filamentous species of algae, which grow in long strands. These algae eventually tangle together, forming thick mats that can double their weight within 24 hours. Blanket weed or string algae tend to adhere to rocks and waterfalls, which can be highly unsightly.

String algae hangs from rocks in waterfalls, attaches to plants, or simply hangs on the surface of the water (then called Blanket Algae). Do not confuse string algae with the soft, velvety, jelly-like coating that forms on the sides of the pond. This is good algae. The fish like to eat it and it contains beneficial bacteria. When your pond has this kind of algae, generally, it is balanced. String algae can be brought in by water plants, so pull off any stringy algae you see on new plants before introducing them into your pond.

String algae is not known for directly creating health problems for fish but causes problems with water clarity and the overall appearance of the pond. As a result, many attempts are made to eliminate the algae by a variety of methods. A few of the methods that have been used for both suspended algae and string algae are detailed in the resources below. Regardless of the approach, you may find that you ultimately must deal with reducing the nutrients that fuel the algae growth cycle.