About Pond Algae

Author: Kacie Guista

Some Basic Kinds of Algae

Algae is natural in your pond. And it is beneficial. But to a point. As noted by Kasco Marine, there are several basic kinds. Planktonic algae are essential, single-celled plant forms occurring worldwide. A healthy pond needs this form of algae as a food source. Filamentous algae is typically found at the surface of ponds in "greenish mats." This kind of algae has little if any value to your pond and looks scummy. The third major kind of algae is attached-erect algae. The fourth kind to be mentioned here is blue-green algae, probably the worst when it comes to pond scum.

Costs and Benefits

Algae is beneficial to ponds, as it provides a food source; in fact, pond owners who desire to raise trophy bass sometimes fertilize their ponds to keep planktonic algae production high. But algae poses several problems, too. For one thing, too much of certain kinds of algae is plain ugly. For another, too much algae is unhealthy. Photosynthesis requires sunlight, and algae blocks it. During the photosynthesis process when plants use sunlight and carbon dioxide to produce food, they give off oxygen. Photosynthesis is a good process for your pond. The plants are using carbon dioxide and giving off oxygen which is needed for your fish, the decomposition of organic matter, and other processes within your pond. However, photosynthesis only occurs when there is sunlight. As the sun goes down, plants turn from oxygen-producing organisms to oxygen-consuming organisms. Therefore, the more aquatic plants and algae you have in the pond or body of water, the more oxygen they will give off during the day and the more they will consume during the nighttime hours. As the night goes on, the oxygen levels continue to decrease. The lowest levels of oxygen will be just before sunlight in the morning before the algae and plants start producing oxygen again. If your pond has too much plant life, the oxygen levels can decrease to the point that large fish struggle to live.

The Problem of Algae Blooms

An algae bloom is a rapid reproduction and spreading of algae when conditions are right. Algae blooms typically occur during the hot, sunny, calm part of the summer. When an algae bloom occurs, your pond can be covered with algae in a very short period of time. The major problem with an algae bloom is the algae die off. Often even quicker than the bloom itself, the algae die off can create major problems. A die off of an algae bloom can be caused by a cloudy day and lack of sunlight, a cold front, storms, etc.

When the algae bloom dies off, it adds a large amount of dead organic matter to your pond. This organic matter is decomposed by micro-organisms at the pond bottom. With the added organic matter load on the pond, the total amount of decomposition occurring in the pond increases and the decomposition process uses up oxygen and gives off carbon dioxide.

This causes two problems. The first is lack of oxygen. When the oxygen in the pond is used to decompose the dead algae, it is not available for fish and other aquatic life. A die off can be so severe that most of the available oxygen in a pond can be used up in the decomposition process and your fish and other aquatic life will start to die off. The larger the organism, the more oxygen it uses. Therefore, your larger fish that have been in your pond for several years will be the first to die when oxygen is taken up.

The second problem with a large die off and increased organic matter is nutrients. When the algae die off and are decomposed the carbon dioxide and nutrients are released back into the pond and is available for the next generation of plant material. The carbon dioxide and nutrients help to begin the cycle all over again.

How to Help Your Pond

There is hope for your pond, though. Aeration can protect your pond and your fish during an algae bloom and die off. Adding an aeration device, such as a Kasco Pond Aerator or other brand of aerating fountain will provide added oxygen to the water and help buffer the effect of an algae die off. When the algae die and are being decomposed, the added oxygen allows the decomposition process to occur properly and also provide oxygen for the fish and other aquatic organisms. By splashing the water in the air, the aeration device is not only adding valuable oxygen, it is also helping to vent gases such as carbon dioxide which is being produced in large amounts from the decomposition process.

Using a pond aerator or aerating fountain will also help prevent an algae bloom in the first place if it is installed before there is a major problem. As discussed above, the added oxygen will help the decomposition process and actually make that process occur quicker. It will also vent the extra carbon dioxide. This means there will be less available for the algae to use, which is one of the key components to blue-green algae problems. Adding an aerator or circulator will also create surface agitation in the pond or body of water. This is beneficial in a few ways. First, it helps eliminate the still stagnant water areas and mimics natural wind. As stated above, algae and algae blooms typically occur in the hot, calm, sunny times of the year. The agitation at the surface that eliminates the stagnant areas decreases the areas algae have available to them to thrive. Just simple movement of the water will help limit the amount of algae present in the pond. Just think, when's the last time you've seen a lake that always has ripples or a river covered with algae? Algae do not like moving water or surface agitation.

Surface agitation is also beneficial because it helps to mix up the algae that is already present within the water column. Algae is not able to sit at the surface of the water and soak up all the sunlight it needs for photosynthesis and it cannot survive without large amounts of sunlight. The agitation also helps to destratify the pond by mixing up the water and limiting the negative effects of turnover. With water that has been thermally destratified, the pond is now more hospitable for desired plants and algae species and creates a better pond ecosystem.

Other Ways to Help Your Pond

There are many other ways to help the ecosystem of your pond, including using herbicides, bacteria and microbes, dyes, ultraviolet sterilizers, barley straw, copper, skimmers, fish, peroxides, and aluminum sulfate, To find out more about algae in detail, we recommend that you read about aerating fountains and algae at Kasco Marine, Inc. If you are looking to purchase a floating fountain or aerator, you might also go to Fountain Mountain.

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