If you ask anyone with a pond what their biggest problem is, then most likely you will get the same answer: pond algae!  Although this green, creeping plant is not really a life-threatening problem, they still use up oxygen.  The more oxygen the algae use, the less oxygen there will be for your pond fish and water plants.

Fortunately, there are different things that you can do to address your algae problem.  If you are wondering how to keep your pond clear and algae free, then read on.  But first, let us talk about what exactly algae is and what the different kinds of algae are.

Different Kinds of Algae

In order to know how to eradicate pond algae, we need to know what exactly it is.  Basically, algae is a primitive kind of plant that sustains itself by producing sugar through photosynthesis. It does this by combining carbon dioxide and water. In the process, the algae produces oxygen, which is actually useful when you think about it.

However, without sunlight, the algae quickly undergoes respiration, which leads to the formation of carbon dioxide at night.  The carbon dioxide ends up depleting the oxygen in the pond, thus depriving the fish and plants of this precious element.

Notably, algae come in two different kinds: green water algae and string algae.

Basically, green water algae are single-celled plants that are so small that they are able to go through even the smallest filter.  They can multiply very quickly — as much as five million cells per milliliter of water — particularly when the conditions are just right.  Wherever there is a body of water that has a lot of nutrients and sunlight, you can expect that the algae population will thrive.

As the name implies, string algae grows in the form of strings or long strands.  They tend to cling to pond rocks and waterfalls.  They can also multiply quickly in just a matter of 24 hours.  If you can observe a thick and tangled mass of green in your pond, then most likely you have string algae, which is also called “hair algae.”

How to Keep Your Pond Clear and Algae Free

Whether you have green water algae or string algae in your pond, you need to eliminate these for the sake of keeping your fish and plants healthy.  Here are some techniques that can help you eradicate as well as remove algae from your pond:

1. Adding Plants

In a natural ecosystem, the fish produces nutrients, which are absorbed by the plants.  However, if your pond does not have enough plants to absorb them, the extra nutrients accumulate in the water.  This, in turn, becomes an ideal environment for algae to grow and multiply.  In order to prevent this, you need to add more oxygenating plants to your pond.

There are different kind of plants that you can use to prevent the growth of pond algae.  First of all, there are floating plants that can help reduce the amount of sunlight that goes into the pond.  The lotus and water lily are examples of floating plants.  You can also include submerged plants like parrot’s feather, horn-wort, and anacharis, all of which can release more oxygen into the water.  The general rule is to place six to seven strands of such plants per two square feet of water.  You can submerge these plants by planting them in a soil container or by tying them to the pond rocks.

Once you add plants into the pond, you may notice that green water algae will occur.  However, these will only survive for a short period.  After some time, you will notice that the water will become clearer and algae-free.  In fact, adding plants is a simple yet effective solution that can keep your water clear and free from algae in the long run.

2. Using Water Treatment

But what if you already have an existing algae problem that you want to address as quickly as possible?  You can try applying a water treatment that is designed specifically for controlling pond algae.  For best results, remember to follow the water treatment instructions properly.

3. Feeding the Fish

What kind of fish food do you use?  As much as possible, use only high quality food in feeding your fish.  This way, the fish will be able to digest the food fully, thus minimizing the nutrients that they release into the water.

4. Using an Ultraviolet Clarifier

If you want to try a more modern method of killing algae, then you might want to consider using an ultraviolet clarifier.  The clarifier has a fluorescent bulb which produces a high level of ultraviolet (UV) light.  High amounts of UV light can destroy the algae’s ability to multiply.  How does it work?  Basically, the water passes through the tubular fluorescent bulb and goes around the UV light.  The UV light then destroys the algae and clumps them together, making them big enough to be removed by the filter.  As the dead algae and other impurities are filtered out, the cleaned water goes back into the pond.

You need to be careful when using an ultraviolet clarifier, though, as UV light can harm your eyes.  You need to place the bulb in a dark and opaque case before you turn it on.

5. Using a Net or a Garden Hose

Despite adding plants, using a water treatment, or an ultraviolet clarifier, you may still find string algae clinging persistently to your pond rocks and surfaces.  When this happens, you will need to remove them manually by using a net or by blasting them with water from a garden hose.

Maintaining a Balanced Environment

Now that you have read about how to keep your pond clear and free of pond algae, always remember that it is important to maintain a balanced environment.  These days, you can use water treatments, UV clarifiers, and other kinds of technology to get rid of algae.  However, you can also keep them in check by adding oxygenating plants.  This way, you can prevent algae from dominating your pond naturally.