Pond algae is often a catch-all for all aquatic plants and aquatic plant related problems. However, not all aquatic plants are algae. Also, not all algae in a pond is created equal when it comes to how desirable or undesirable it is in your pond.

Part of the reason many call all aquatic plants pond algae is because even experts differ on what to call or classify algae. Defining algae in a pond is very difficult, but basically, algae is a simple organism that can be composed of one cell or many cells grouped together in a colony. There are three basic types of pond algae:

• Planktonic algae
• Filamentous algae
• Attached-erect algae

Planktonic Algae

Planktonic pond algae are single-celled, microscopic plants which are distributed worldwide. Blooms can be bright green, pea soup looking or even a blood red color. They are the base of the food chain, and a healthy existing pond or well prepped new pond must have planktonic algae as a food source.

Filamentous Algae

Filamentous pond algae are called many things such as pond scum or moss, and they are typically found at the surface in the form of greenish mats. Typical growth begins on the edges of ponds and will slowly rise until it arrives at the surface. This series of cells joined together has a slimy, cottony or course texture. It can look like the stringy masses covering the Algae Monster or “scum” photos to the right. Filamentous algae in a pond will grow where there are higher levels of calcium and phosphorus. It is common to have this type of algae encouraged after ponds are limed to enhance fish production. Filamentous pond algae typically are of little or no value to your pond.

Attached-Erect Algae

Attached-erect pond algae are non-rooted but dense. A misconception is that it looks like a higher vascular plant, which causes confusion. It typically has a gritty and bristly texture and is not much use to the overall pond health. Blue-Green algae is often the biggest culprit when it comes to “pond scum” problems. Recently, it has been reclassified in the Monera Kingdom which consists of bacteria instead of being classified with other types of algae because the blue-green algae relates more closely to bacteria than other forms of algae. Within the blue-green algae grouping, there can be several varieties that can have many different colors such as red, brown, or yellow. Blue-green algae are nitrogen-fixing organisms and only need nitrogen and carbon dioxide to live, both very prevalent in most ponds. When there is a blue-green algae bloom, it forms dense masses on the surface of the pond and can cover the entire body of water. In fact, it is believed that the Red Sea was given its name from a red species bloom of blue-green algae.

These are some of the most common types of pond algae our customers call us about. With warmer months ahead of us, now is a great time to start thinking about spring pond maintenance and preparing for the algae you might see start to build up on your pond. Not sure where to start or have questions? We’ve got you covered. Give our team a call at 715-262-4488 or email us at support@kascomarine.com and we’ll help with your pond algae questions.