Planktonic algae are free-floating microscopic plants that suspend in the upper layers of the water. The community is generally composed of green algae, blue-green algae, diatoms and euglenas and is green or brown in color. An important part of the food-chain, planktonic algae are a food source for microscopic animals as well as freshly hatched fish fry. However, some species can be toxic to animals. The amount of planktonic algae present varies from season to season. Being plants, planktonic algae need sunlight and nutrients to flourish, so levels are lowest in the winter. As temperatures increase, spring blooms occur. The plants will then be depleted by the animals that feed on it. Planktonic algae levels will increase again in late spring but, generally, not to the levels of the spring bloom and will usually remain stable throughout the summer months. Summer blooms can occur, however. The levels will then decline in the fall as the water cools.
Planktonic algae are always present and preventative measures are often sufficient to keep the levels stable. A pond dye, such as AQUA DOC Blue will shade the water which limits photosynthesis and controls the growth. Shading is particularly effective when applied in early spring to prevent initial growth. However, extra nutrients in the water from sources such as lawn fertilizers and goose excrement feed the algae and blooms can occur. Severe blooms are a concern for many reasons ranging from aesthetics to oxygen depletion and possible fish kills. Copper sulfate and Cutrine Plus are common treatments for planktonic blooms, however several treatments are often necessary as re-blooms can occur. Both products are available for order on our website. Always read the product label before use.