What are Algae?
Algae are a diverse group of photosynthetic plants that occur in a wide range of environmental habitats. As plants they contain chlorophyll and have simple reproductive structures. Unlike most plants, their tissues are not differentiated into true roots, stems or leaves. They range from single cells to fairly complex multi-cellular organisms. Some algae, like Chara, have such a complex structure that they are mistaken for vascular plants.
An individual microscopic single cell algae plant is about 0.001 mm in diameter or about 25 times smaller than a human hair. Algae are found throughout the world and are a general nuisance in water treatment plants, drinking water supplies, irrigation reservoirs, fish ponds, water impoundments, water gardens, swimming pools, and cooling towers.
These microscopic single-celled forms of plant life thrive in sunshine. They are present on vegetation, in the air, in the soil, and in water. Their microscopic spores are continuously introduced into pools and other bodies of water by wind, dust storms, rain showers, etc.
They grow rapidly in stagnant waters when exposed to sunlight and temperatures above 39ºF. They can form objectionable slime and odors. They can interfere with filtration systems and irrigation nozzles. They can greatly increase chlorine demand in pools and cooling tower systems. Phosphates and nitrates in the water from fertilizer and land runoff encourage their growth.
Algae have three basic forms: Planktonic, filamentous and macrophytic. Planktonic algae are single-celled, microscopic plants that float freely in the water. When these plants are extremely abundant or an algal bloom occurs, they make the pond water turn green. Less often, they can turn the water other colors, including yellow, gray, brown or red.
Filamentous algae are sometimes referred to as "thread algae" or "pond scum." Filamentous algae occur as fine green threads that form floating mats, which are often moved around the pond by wind. These algae are also commonly found attached to rocks, submerged trees, other aquatic plants and boat docks.
Macrophytic algae resemble true plants in that they appear to have stems and leaves and are attached to the bottom. A commonly-occurring macrophytic type of algae is called chara or musk grass due to its strong musky odor. Chara feels coarse to the touch, because of lime deposits on its surface, earning it another common name -- stonewort.
For the most part, algae are of little value to your pond or lake. The filamentous and planktonic forms can reproduce at phenomenal rates and sudden die-offs can cause oxygen depletion. The necessary oxygen required in fish ponds or lakes can be supplied by other aquatic plant life in the water basin and these aquatic plants typically flourish without algae competition.
Algae problems are usually caused by an overabundance of nutrients (nitrogen and phosphorous) in the pond.
From the moment a pond is built, it becomes a settling basin for nutrients washing in from the land or watershed that drains into it. As a pond ages, more nutrients accumulate in it making it more susceptible to algae problems. Runoff from fertilized fields, lawns and pastures, feedlots, septic tanks and leach fields accelerate nutrient loading and algae growth in the pond.
Excessive algae growth will starve or strangle other forms of aquatic plant life, as well as block out sunlight necessary for their proper growth. Taste and odor problems in drinking water and sometimes even fish kills are associated with excessive blooms of planktonic algae. Filamentous algae and macrophytic algae often form dense growths that make fishing, swimming, and other recreational uses nearly impossible. Total coverage can restrict sunlight penetration and limit the production of oxygen and food items necessary for good fish growth. When algae abundance interferes with the intended use of the pond, a control method should be considered.
Algae control methods do not always give the desired results. For example, mats of filamentous algae may be removed with a rake, screen wire, or similar devices; however this control method is very labor intensive and provides only temporary control. In some instances, the algae may seem to grow as fast as they are removed. Before using chemicals, you should consider potential contamination of domestic water supplies and the waiting periods for watering livestock, eating fish, swimming and irrigation. In general, you must have a license to dispense many of the chemicals used as algaecides.
A "biological control" typically uses one form of life to control another or the balance of life is manipulated in some way to adversely affect an undesirable pest. It is wise to be very cautious when deciding on the use of a biological control. It can backfire when the introduced species becomes more of a problem than the original pest. One such agent is barley straw that has been used with mixed success. It is generally classed as an algistat or growth inhibitor, rather than an algaecide or algae killer. It appears to have more effect on planktonic algae and has in some tests caused the filamentous algae growth to accelerate. At any rate, it may help but will not totally eliminate the problem.
Now there is a better way to control algae. It is environmentally friendly, cost effective and chemical free. The method is not revolutionary technology. It was discovered decades ago that ultrasound would destroy algae cells. However, at the time of the discovery, ultrasonic wave generators were too costly to make it a marketable product. But today, underwater ultrasonic sound wave generation that is inaudible to and no threat to people, animals, fish or plants is now available and affordable for those who want to get rid of algae and other harmful micro-organisms such as destructive root parasitic fungi, Fusarium and Pythium.
The new Sonic Solutions SS 600, SS 500, SS 400, SS 200, and the SS 100, destroy nearly all forms of algae without chemicals.