How to Get Rid of Algae in a Pond

Algae Removal Pond Advice pond care Pond Cleaning

For every pond keeper, there is one word that instils terror in their entire beings. Algae. This entirely unwelcome plant life will invade your pond, turning the water green and leaving a sludgy film that obscures your fish and plants in the water. Plus, it can also be very harmful to your pond life, as it is known to deplete valuable oxygen.

If you're tired of battling green water and slimy growth, you've come to the right place. With over 40 years of experience in pond care, we at Pond Planet are here to share our expert advice on how to effectively remove algae from your pond and then how to prevent it from returning.

Contents

What is algae?
How to remove algae
How to remove algae fast
How to remove algae and green pond water naturally
How to remove string algae from ponds
FAQs around green pond water
How to prevent and control algae

What is algae?

Algae are a primitive plant created through photosynthesis, combining water with carbon dioxide to create sugars that promote energy and growth. At first, algae will produce oxygen, but this is only true under sunlight. When nighttime comes, the algae will respire and use their stored sugars and oxygen to create carbon dioxide. This, in turn, will deplete the oxygen in your pond and be harmful to the other plants and fish in your pond.

Two types of algae

Before treating algae, you should be aware that there are two different types that will be treated differently.

Green Water:
As the name suggests, this type of algae will be the cause of your green and murky pond water. They are single-celled organisms that remain suspended in water and are actually so tiny that they pass through even the finest of filters. In the right conditions, there can be as many as five million algae cells per millilitre of pond water.

String Algae:
This algae is also commonly referred to as ‘blanket weed’, and it is the more obvious form of the two types. Growing in long strands, string algae will plant itself on walls and waterfalls in your pond before eventually tangling together. These tangles then form together to form a thick mat that is unsightly in the pond and can double its own weight in a matter of 24 hours.


How to remove algae

Effectively removing algae from your pond often requires a combination of immediate treatments and long-term prevention strategies, depending on the type of algae present.

How to remove algae fast

If you’re looking for a straightforward removal of algae, then you should choose a relevant water treatment for your pond. A pond treatment is an excellent option for tackling established algae growth. Plus, it can be effective on both green water and string algae when used correctly and repeatedly.

Important Note: Don't expect a single application to solve your algae problem entirely. For optimal results, always follow the treatment instructions carefully and be prepared for repeated applications as recommended.

 

Shop pond water treatments

 

How to clear green pond water fast

The best green pond water treatment is to use a high-quality UV clarifier.

  • How it works: A UV clarifier exposes suspended, single-celled algae to ultraviolet (UV) light as water passes through it. This exposure destroys the algae's reproductive capabilities, preventing it from growing and multiplying, causing it to clump together and be removed by your filter.
  • Safety first: UV light can be harmful to humans. A reputable UV clarifier will feature a tubular fluorescent bulb that emits UV light, safely enclosed within dark housing to protect your eyes. Always ensure the unit is installed correctly and never look directly at the UV bulb when it's operating.


How to remove string algae from ponds

Unlike green water, string algae cannot be controlled by UV clarifiers and requires a more manual approach.

  • Hands-on: It's time to roll up your sleeves! The most straightforward way to remove string algae is by physically pulling it out with your hands or a pond net.
  • Loosen it up: Before manual removal, try blasting the string algae with your garden hose from its attachment points on rocks and waterfalls. This can help loosen its grip, making removal easier.

How to remove algae and clean green pond water naturally

To remove algae from your pond naturally, add plants. In a natural pond setting, plants will absorb the nutrients produced by fish, meaning there are few to no nutrients left for algae.

In most garden ponds, there is not a sufficient amount of plant life to handle the excess amount of nutrients. The resulting build-up of nutrients in the water is like a wonderland for algae and is the prime condition for it to grow, form and spread.

So, whether you’re just beginning your pond journey or you’re looking for a way to control your algae levels, then choosing the right pond plants and tools is a must.

  1. Oxygenating Plants: Start by increasing the amount of oxygenating plants on the surface of your pond, as this is the simplest and easiest addition to keep your water clean and clear.

  2. Floating Plants: To reduce the amount of direct sunlight reaching the algae in your pond – a key factor in its growth – introduce floating plants like water lilies or lotus plants. Their broad leaves provide shade, effectively starving the algae of light.

Learn more about how to choose the right pond plants.

FAQs around green pond water

Why is my pond water green?

Pond water is usually green because of an overgrowth of microscopic algae. It is basically caused when you have an imbalance in your pond of too much food and light for the algae, causing them to multiply rapidly and turn your water green.

This is primarily due to:

Excess nutrients: Too much fish waste or decomposing organic matter (like leaves).

Too much sunlight: Algae thrive on sunlight, so ponds in direct sunlight are more susceptible.

Inadequate filtration: Your filter might not effectively remove the tiny algae particles or process enough of the waste.

Not enough pond plants: Plants compete with algae for nutrients; if you don't have enough, algae win.

Is green pond water bad for fish?

Algae in ponds can be bad for fish as the algae and the bacteria decomposing them consume large amounts of oxygen, leading to dangerously low levels that can suffocate fish. Dense algae can cause drastic daily fluctuations in pH, which stresses fish and makes them vulnerable to disease.

How to stop pond water from going green

Preventing green pond water primarily involves maintaining a balanced pond ecosystem. No pond, whether it's a natural ecosystem or a carefully designed garden feature, will ever be entirely algae-free. However, under balanced conditions, algae can be effectively controlled and managed.

Say goodbye to pond algae for good and enjoy crystal clear water

Now you have the knowledge and tools to combat algae and keep your pond looking its best effectively. Remember, achieving a beautiful, balanced pond is an ongoing journey, but with the right approach and a little patience, you can enjoy a vibrant, healthy aquatic environment.

At Pond Planet, we've got everything you need to win the fight against algae:

Shop our full range of pond water treatments to find the perfect solution for your specific algae problem. Explore our powerful UV clarifiers designed to eliminate green water and keep your pond sparkling.

Discover our selection of pond plants and tools to naturally control algae and enhance your pond's ecosystem.

Still have questions or need personalised advice? Don't hesitate to contact our expert team or visit us in-store.

Read more

How To Clean A Pond
Pond Sludge Tips: What It Is and How to Remove It for a Healthier Pond
How To Remove Blanket Weed
The 5 Different Types of Pond Plants and The Best Ways to Plant Them

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