| Pond Algae is a loose term that describes the | | | | remaining algae, starting the process off all over |
| different species of algae, commonly found in fish | | | | again. |
| ponds. Some forms of algae are of benefit to the | | | | * The decaying process consumes oxygen from |
| pond system whereas others can be considered | | | | the pond water. This is particularly bad for the |
| to be more of nuisance. It is important to prevent | | | | nitrifying bacteria and pond fish species, which |
| algae blooms if you want to keep your Koi and | | | | need oxygen to survive. Remember that |
| other pond fish alive. | | | | ammonia needs to be converted into nitrites and |
| Common Pond Algae Types | | | | then into nitrates by the nitrifying bacteria. The |
| The most common variety is the suspended or | | | | oxidization process requires vast quantities of |
| floating green algae, such as Chlamydomonas, | | | | oxygen in order to occur. |
| Chlorella and Euglena species. These microscopic | | | | * The increase in ammonia, which is also produced |
| unicellular organisms grow to about 4 microns in | | | | by rotting algae matter, places additional strain on |
| diameter (4 millionths of a meter). They multiply | | | | the pond filter that houses the nitrifying bacteria. |
| rapidly by means of spores, cell division or | | | | Methods commonly used To Control Pond Algae |
| fragmentation. These green algae varieties are | | | | * The most successful and in my opinion the only |
| sometimes known as pea soup algae because | | | | really effective method of controlling floating |
| they will in extremely high numbers turn your | | | | planktonic algae is to use a UV sterilizer or UV |
| pond into something that resembles a bowl of | | | | clarifier. The ultraviolet light bombards the single |
| pea soup. | | | | celled algae, causing it to die and stick to other |
| Filamentous string algae look like long green hair | | | | dead algal cells. |
| and have a thread like appearance, due to a | | | | * Try where ever possible to remove as many |
| series of cells joined end to end. Horsehair algae, | | | | of the nutrients from the pond as possible. |
| also known as Pithophora and blanket weed | | | | Nutrients, mainly in the form of nitrate and |
| varieties such as Cladophora, Oedogonium and | | | | phosphorous act as a food source for the pond |
| Spirogyra are particularly common. | | | | algae. A good habit to get into is to remove |
| What Causes Pond Algae To Grow? | | | | excess fish food after feeding and to remove |
| The three factors that allow pond algae to | | | | floating surface debris with a pond net. When |
| develop are clear pond water that allows sunlight | | | | feeding pond fish it is better to feed little and |
| to penetrate, nutrient rich pond water and heat. | | | | often, so as to prevent waste. |
| An increase in temperature accelerates both | | | | * Try to cover at least one third of the surface |
| suspended green algae and blanket weed growth. | | | | area of the pond with pond plants, as they |
| How Do The Various Pond Algae Types Affect | | | | compete with algal cells for the available nutrients |
| My Pond? | | | | in the pond water. |
| Suspended planktonic algae multiply at a rapid rate | | | | * Perform routine cleaning by removing blanket |
| and can only really be controlled by ultra violet | | | | weed and string algae with a rake. |
| light from a UV sterilizer or UV clarifier. The UV | | | | * The use of barley straw products will help to |
| light breaks the cell walls, causing the algae to | | | | inhibit the algae growth. Barley straw bales are |
| clump together. As they stick together the mass | | | | best placed in the pond in early spring, where the |
| becomes bigger, making it possible for it to be | | | | natural decomposition releases chemicals in |
| filtered out by a biofilter. Excessive suspended | | | | preparation for summer when nutrients and |
| green algae form what is known as algae blooms. | | | | sunlight are at their peak. |
| They can be catastrophic to pond fish populations | | | | * The Centre for Aquatic Plant Management has |
| as they will eventually starve the pond of oxygen, | | | | discovered that ultrasound waves are proving to |
| particularly in hot temperatures, where | | | | be one of the best solutions in the fight against |
| atmospheric oxygen can not be absorbed into the | | | | blanket weed. The ultrasound breaks down the |
| pond as easily. | | | | cell walls, causing death within 3 weeks. This is at |
| Blanket weed and string algae varieties, multiply | | | | present an expensive treatment and requires |
| rapidly and form long, slimy clumps that attach | | | | specialist installation. |
| themselves to any available surface. They | | | | * The use of pond algaecide treatments is |
| consume large quantities of nutrients and will tend | | | | common practice, but is in my opinion not a good |
| to be a dominant species. Once blanket weed | | | | idea. These chemicals can cause harm to pond |
| forms in your pond it is almost impossible to get | | | | fish, nitrifying bacteria and pond plants, if over |
| rid of. | | | | dosed. |
| Why Is Excessive Pond Algae Bad For Garden | | | | To conclude I would like to add that some pond |
| Ponds? | | | | algae is beneficial to the pond, as it provides a |
| * It not only makes the pond look untidy and | | | | source of food for fish, provides shade from the |
| over grown but can in worst case scenarios | | | | hot sun and provides a hiding place from heron, |
| actually cause the pond to smell. | | | | king fishers and other predatory birds. It is natural |
| * As algae blooms and filamentous string algae die | | | | to have some algae growth on pond surfaces, |
| they start to decay on the pond floor, where | | | | pond filters, pond pumps and other pond keeping |
| they give off carbon dioxide. The increase in | | | | equipment. The secret is to keep it under control. |
| carbon dioxide acts as a food source for the | | | | |