Six Home Remedies for Algae in the Pond

Six Home Remedies for Algae in the Pond

Algae can be quite a nuisance to your garden pond and the inhabitants in it. If the water is rich in nutrients, many algae settle. Especially in the summer months, when temperatures are high, algae can multiply rapidly. Not only do they make the water cloudy, but they can also cause the water to tip over. This inevitably means the death of your fish. If you want to avoid this, you don’t always have to resort to chemicals. It is much cheaper and gentler to use home remedies. With the following six home remedies, you can restore clarity to your garden pond.

Why Biological Algae Control is Useful

Even if you carefully maintain your garden pond and remove leaves that have fallen into the pond, you cannot prevent the formation of algae. If you have just created the garden pond, the water is expected to turn green after a short time. This is due to the floating algae that form, as the ecosystem in your pond must first build-up. Algae must even be present to a certain extent. They are an indication that your pond is in an ecologically correct state.

In the spring, algae blooms occur. Tiny suspended algae cloud the water. If the ecosystem in your pond is in order, the turbidity will disappear naturally on its own after a few weeks. The water is then clear again.

However, unfavorable conditions and different weather patterns can cause increased algae growth. To quickly make the pond clear again, many pond owners resort to chemicals. In the long run, these agents harm not only flora and fauna in your pond but also the environment. It is relatively environmentally friendly and completely harmless to the animals and plants in your pond are home remedies, as they are biologically harmless.

Algae growth is promoted by various factors, such as leaves that have fallen into the pond and a high concentration of nutrients in the water. If the sun shines directly into the pond for long periods, the algae can multiply well, just as they do during extended periods of heat. If the water is warm, the algae can grow better. Pollutants such as phosphate and nitrate in the water also promote algae growth. With rainfall, plant debris and soil often enter the water, encouraging algae proliferation. If there are too many fish in your pond, the algae get a lot of nutrients with the fish’s excrements. Food remains, and fish excrement enriches the water with nutrients. You should not use garden soil for your plants in the pond, as it contains too many nutrients. Special pond soil is more suitable.

You can use the following home remedies individually but also combine them. If your pond is heavily infested with algae, you can get it free of algae again with a combination of several treatments.

1. Remove Algae Mechanically

The easiest way to get your pond clear again is to remove algae mechanically. This takes some time, but it is effective. Get to grips with the algae mechanically regularly, and you will make your work easier, as you will have to invest less time in it in the future. The more often you remove the algae, the worse they can multiply.

When removing algae mechanically, you can also remove pollen and leaves that have fallen into the pond simultaneously. You should also regularly check your aquatic plants for dead plant parts and remove these parts. Such plant parts can quickly decompose and increase nutrient inputs.

While filamentous algae are a nuisance and can significantly detract from the pond’s appearance, they provide adequate protection, especially for smaller animals. If you remove the filamentous algae, you should allow these little animals to get back into the water. Therefore, you should place the removed algae and plant parts near your pond and only finally remove them after about an hour.

Filamentous algae can form very long, thin filaments. However, they are pretty easy to remove. There are special algae brushes that you can use to remove the algae quickly. A stick that you turn in the water is also good. The filamentous algae will wrap around the stick like spaghetti. You can also fish off the algae with a landing net.

If you remove the algae mechanically, you should proceed carefully and not damage plants in the pond. Dispose of the algae removed from the pond in the compost. There they will still serve a useful purpose, as they will be composted into valuable humus for your garden.

Pond mud vacuums are also perfect for algae removal. With a suitable suction attachment, such as a suction nozzle, you can very quickly rid your pond of algae.

2. Water Pump and Filter for the Pond

If you want to be successful in the long term in the fight against algae, you should equip your pond with a water pump. The constant exchange of water provides movement and counteracts the formation of algae in the long term. Ideally, you can even get your pond free of algae. Most algae species prefer calm or stagnant waters and love higher temperatures. The water pump provides cooling of the pond water through movement.

You should install the pump in an open area of the pond where there are no aquatic plants. The pump circulates the water and provides fresh oxygen to the pond.

You can also provide water movement by installing water features or a fountain.

In addition to the water pump, you can add a filtration system to your garden pond. Filter systems are recommended if you have a lot of fish living in your pond.

Which pump and filter you choose depends on the volume of your garden pond. Before buying, you should familiarize yourself with the product descriptions for these devices.

Filters clean the water and enrich it with oxygen.

To prevent the formation of algae, you can also use a pond clarifier with UVC light. The ultraviolet light fights germs and counteracts algae growth.

3. Shade Garden Pond

If you are creating a new garden pond, you should use a semi-shaded location if possible. A house wall or trees will provide shade, but leaves falling into the pond will encourage algae growth. If the garden pond already exists and is located in a sunny spot, algae infestation is promoted by the sun’s rays. Especially the blazing midday sun makes the algae grow. Even if your pond is exposed to intense sunlight, you can do something about the algae. Shading is effective. For smaller ponds, you can use a parasol. You can shade larger ponds with awnings.

Shade can also be provided by various aquatic plants thanks to their growth habit. Such plants can spread a kind of roof over the pond. Reeds can shade the pond, but they are only suitable for larger ponds, as they increase a lot. It would help if you kept the reeds under control to stop them from reproducing too much. Planting perennials or shrubs near your pond can also provide shade.

4. Regularly Control and Regulate the pH Value

The standard control and regulation of the pH value are essential to prevent algae formation in the garden pond. An incorrect pH value can promote a heavy algae infestation. To check the pH level, you can use test strips. You can also do the droplet test. Such test sets contain everything you need for pH determination but also for measuring other values. With the droplet test, the measurements will be even more accurate than with the strip test. You can also determine the water’s nitrate, phosphate, nitrite, ammonia, and iron content with the droplet test.

If the pH is too high, it will favor the algae growth in the long run. Often, if the pH is too high, it is sufficient to replace part of the water.

In the morning, the pH value is lower than in the evening. Various external influences cause the pH value to climb. This is completely normal and indicates a well-functioning pond environment. The water is then relatively clear and provides good growing conditions for aquatic plants.

A neutral pH is around 7. For your garden pond, a pH between 6.8 and 8.2 is ideal. To regulate the pH, you can replace part of the water and place an oak branch in the water. It releases tannic acid and lowers the pH. However, you should not leave the oak branch in the pond for more than one season, or it will decompose. For a lower pH, you can also place a jute bag with peat in the pond. The jute bag should be in a suspended position if possible. Despite these precautionary measures, you should measure the pH regularly. You should replace the peat after three to four weeks.

If you also regularly check the remaining pond values, you can quickly intervene with the appropriate measures if the values get out of balance.

5. Kill Algae With Vinegar – Proceed Sparingly

As a home remedy to fight algae in the garden pond, vinegar is suitable. Vinegar can kill various types of algae with its acidity. The pH value can be lowered by vinegar. Now and then, milk is also recommended. The effect of milk on algae control has not yet been proven in practice. Milk also contains lactose, proteins, and nutrient-rich fats. These ingredients could even promote the formation of algae and lead to a turbidity of the water. Vinegar is not always the solution of choice either, as it can affect the biological balance in your pond. For the pond inhabitants, this can be highly stressful. If you would like to use vinegar, you should only use it very sparingly. A mixing ratio of 1:2,500 is recommended. Pure citric acid can be better than vinegar. It is more neutral in taste.

6. Aquatic Plants and Animals

A reasonable and natural means of combating algae in your garden pond are aquatic plants and animals. Algae need nitrate and phosphate for their growth. Other aquatic plants also need these substances. If there are enough aquatic plants in your pond, they will deprive the algae of an important food source. In addition, the plants provide your pond with oxygen and shade. Submerged plants and floating plants can clarify the pond water.

Suitable food competitors for the algae are purple loosestrife, water iris, or water hyacinth. In the shore zone, you can plant arrowhead, bulrush, and water bulrush. Lotus, frogbit, water lily, and water pine provide good shade. Water plants and water hoses have a cleansing effect.

You should not forget the visual value of the plants. They enhance your pond and make it a piece of jewelry. You should not use garden soil for your water plants, as it is too rich in nutrients. Low-nutrient pond soil is more suitable.

Animals in the water can also counteract algae growth. It would be best if you made sure that these animals feed primarily on filamentous and turbid algae. Water snails are voracious and will destroy the algae. Shrimp are also good algae destroyers.

Some fish will eat algae, but you should adjust the fish population to the pond size. If the fish population is too high, contamination from fish feces will encourage algae growth. If you feed the fish, you should avoid overfeeding them. Uneaten food forms a good nutrient base for the algae.


In every garden pond, despite intensive care, algae form. You do not need to use chemicals to combat algae, as the delicate ecosystem can be disturbed. Natural means and home remedies are better suited. You should regulate the pH level regularly, use a filter and pump, shade the pond or remove the algae mechanically. Water plants and animals can also counteract algae growth.

Florian Egert

I am Florian Egert, the owner of I live with my wife and two children in Germany in a small village in the countryside.

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