Fighting thread algae in your pond

Thread algae control and prevention in the pond

Are you experiencing problems with filamentous algae in your pond? We completely understand how frustrating this can be. Thread algae can quickly spoil the enjoyment of a clear, beautiful pond. We have struggled with this problem ourselves and know exactly how it feels to have to deal with that pesky algae over and over again.

We are ready to help you!

With our years of experience, we have put together the Complete Anti Algae Pond Package, specially designed to control filamentous algae naturally and effectively. This package is not only environmentally friendly, but also cost effective. No need to buy expensive chemicals that can harm the water. Instead, we offer a 100% natural solution that really works.

Float algae in your pondClear pond
Anti Algae Pond Package: Control and prevent thread algae and floating algae naturally

Oxygen Plants and Bacta Clear are essential for crystal clear, healthy water. Together they increase oxygen levels, eliminating the need for a pump or filter, limiting algae growth and providing a safe haven for fish. Minimum recommendation for pond oxygen plants: at least 10-12 individual plants per m³ and 2 baskets of 4 plants per m²

Simon van der Velde

Pond specialist and aquatic plant breeder
BACTA CLEAR + 2x POND BLOCK

Get rid of your thread algae fast?

Want to get rid of string algae in your pond quickly and effectively? Discover the ultimate solution with Bacta Clear and Pond Blocks. This powerful combination of products offers a quick and easy way to combat string algae and make your pond clear again. With the effective action of Bacta Clear and Pond Blocks, you can quickly enjoy a beautiful, algae-free pond in your garden again.

NOTE: for a structural solution, we recommend the anti algae package

Anti algae pond kits for a year round algae free pond

For a pond from 100 to 15,000 gallons of water

Click on the image for an explanation of how to calculate the number of gallons of water in your pond.

Calculating content of your pond

Anti Algae Pond Package - S

- For 100 - 500 L
- Oxygen plants + extras
- Placement: -1 to -20 cm

Original price was: 107.00.Current price is: 99.95.

In stock

Anti Algae Pond Package - M

- For 750 - 1.500 L
- Oxygen plants + extras
- Placement: -1 to -20 cm

Original price was: 212.00.Current price is: 199.95.

In stock

Anti Algae Pond Package - L

- For 2,000 - 3,000 L
- Oxygen plants + extras
- Placement: -1 to -20 cm

Original price was: 417.00.Current price is: 299.95.

In stock

Anti Algae Pond Package - XL

- For 4,000 - 6,000 L
- Oxygen plants + extras
- Placement: -1 to -20 cm

Original price was: 800.00.Current price is: 499.95.

In stock

Anti Algae Pond Package - XXL

- For 12,500 - 15,000 L
- Oxygen plants + extras
- Placement: -1 to -20 cm

Original price was: 1,955.00.Current price is: 1,499.95.

In stock

Do you have any questions? Simply contact us using our form

We offer 24/7 support, 100% growth and flowering guarantee, and a 30-day money-back guarantee. Our hardy aquatic plants are 100% organic and chemical-free angebaut. Not satisfied? We'll fix it!

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Pond water testing & water improvers vs Anti algae pond package

With pond water testing and water conditioners, you only address the symptoms, not the real cause. This costs a lot of time and money and you have to repeat it often. Our Anti Algae Pond Package is a simpler solution: it ensures that your pond keeps itself in balance. So you get rid of the problem at once and save money.

Pond water testing & water improvers

Anti Algae Pond Package

❌ Regular measurements required ✅ One-time setup
❌ Requires some knowledge ✅ User-friendly and easy
❌ Depending on proper dosage ✅ Direct and effective approach
❌ Temporary solution ✅ Provides sustainable results
❌ Repeat purchases required ✅ One-time investment
review clear pond

Anouk

In no time we had a clear pond again

A pond in the garden is very nice but the water has to be clear. At first we had a lot of algae problems. We asked Van der Velde for advice and they recommended adding an oxygen plant kit and a bottle of pond bacteria to the water. In no time we had a clear pond again and the kids could sit with their feet in the water again!

Verified review

Oxygen plants and Bacta Clear are essential for crystal clear and healthy water.

Bacta Clear and Oxygen Plants create natural balance in the pond, simplify maintenance and promote optimal growth of pond plants. This combination keeps your pond clear, healthy and aesthetically pleasing while respecting the environment.


Natural balance

Oxygen plants provide a clear, algae-free pond without external pumps or filters. Our hardy plants from our own nursery offer a low-maintenance solution with a 100% growth and flowering guarantee.
pond maintenance

Easy maintenance

With 35 years of experience, we offer a clear pond through the unique combination of oxygen plants and Bacta Clear pond bacteria. This approach is 100% natural and safe for all living things, simplifies maintenance and promotes plant growth.
Optimal growth

Optimal growth

Our strategy ensures clear water and strong plant growth by biodegrading waste products. The use of specially selected plant packages makes planting easy, keeping your pond naturally balanced and aesthetically pleasing.

The solution to get rid of your thread algae fast

For a pond of 10 to 10,000 gallons of water

NOTE: for a structural solution, we recommend the anti algae package

BACTA TAB + POND BLOCK

- For 10 to 1,000 L
- Algae free in 10 days
- Thread algae and floating algae control

 24,95

In stock

BACTA CLEAR + 2x POND BLOCK

- For 2,000 L
- Algae free in 10 days
- Thread algae and floating algae control

Original price was: 50.00.Current price is: 44.95.

In stock

BACTA CLEAR + 5x POND BLOCK

- For 5,000 L
- Wire algae free in 10 days
- Thread algae and floating algae control

Original price was: 80.00.Current price is: 64.95.

In stock

BACTA CLEAR + 10x POND BLOCK

- For 10,000 L
- Wire algae free in 10 days
- Thread algae and floating algae control

Original price was: 130.00.Current price is: 99.95.

In stock

This is what our customers say!

Excellent customer review vdvelde.com 200+ reviews at

Frequently Asked Questions

Pond Advice

Pond clarity can be affected by several factors, including the presence of algae, water quality and the balance of bacteria in the pond.

With murky water, it is important to identify the cause. This can range from algae blooms to a lack of beneficial bacteria. Plenty of oxygen plants and a bottle of Bacta Clear are the solution.

Keeping your pond algae-free is achieved by maintaining a healthy balance between the pond plants, pond fish and bacteria in the pond. Using Bacta Clear helps keep algae away.

It depends on the extent of the problem and the solution used. With oxygen plants and Bacta Clear, improvement can be seen within a few weeks.

The anti alga pond package includes 4 types of loose oxygen plants; waterweed, hornwort, crabgrass and moss balls. These aquatic plants grow just below the surface of the water so they keep the sun out of the water in the summer and add oxygen to the water. The convenience of these plants is that you throw them loose in the pond and you don't have to worry about them.

Advice and tips

oxygen plant category

All oxygen plants

Pond bacteria bacta clear

Pond Bacteria

Substrate pond substrate

Pond substrate

Pond Plants

Everything for a natural pond

Float algae in your pond

Controlling thread algae and floating algae

Thread algae and floating algae are two types of algae that can make ponds murky. Controlling thread algae and floating algae in the pond with lime is a common method. A more natural and effective way to make pond water clear by fighting algae is to add Bacta Clear to the water. BactaClear also stimulates the growth of aquatic plants which, together with the bacteria, restores the biological balance in the pond and keeps it healthy. One bottle of Bacta Clear is sufficient for 20,000 liters of water.

Controlling algae in your pond

There are different types of algae, including green, brown and blue algae. It can be challenging to control algae in the pond naturally, but with Bacta Clear's pond bacteria, it is possible. There are also other methods of controlling algae in the pond, namely planting enough oxygenated plants and other types of aquatic plants. Furthermore, a layer of pond substrate on the bottom should not be missing.

What is filamentous algae?

Thread algae, also known as filamentous algae, is a type of algae found in ponds and other bodies of water. They are long, thin threads that stick together and form a dense layer. This can give an unsightly appearance to the pond and affect water quality. Excessive growth of filamentous and floating algae can reduce oxygen levels in the water, which can be dangerous to pond fish and other aquatic organisms in the pond. Fortunately, thread algae can be easily and quickly controlled and prevented by properly landscaping the pond.

What is the cause of filamentous algae?

Thread algae begin innocently as gossamer strands that attach to the pond edge, plants or rocks. Causes are:

  1. Insufficient oxygen plants: Thread algae and oxygen plants are food competitors. If there are not enough oxygen plants to absorb nutrients from the water, filamentous algae have a growth advantage.
  2. Low water hardness: Thread algae grow well in soft pond water, while oxygen plants do not.
  3. Leaf fall: Falling leaves that decay on the pond floor release nutrients that promote filamentous algae growth.
  4. Abundance of fish: Fish produce waste, which makes pond water more nutrient-rich and encourages the growth of filamentous algae.

Is filamentous algae good?

To a limited extent, filamentous algae can contribute to the pond ecosystem by consuming nutrients that might otherwise lead to an explosion of more harmful algae species. However, when they get the upper hand, they can interfere with other plants and disrupt the pond's biological balance.

How do you prevent filamentous algae?

  1. Provide enough oxygen plants: Place enough oxygen plants in the pond so that they can absorb nutrients from the water.
  2. Limit leaf fall: Span a net over the pond to prevent falling leaves.
  3. Limit the number of fish: Too many fish make the pond water more nutrient-rich.
  4. Remove filamentous algae by hand: This helps slow its growth.
  5. The ultimate answer to thread algae is a properly designed pond: A properly designed pond promotes a natural balance, with each plant and organism playing its part in creating a healthy environment. This balance keeps the water clear and prevents excessive growth of algae such as string algae.

Control of filamentous algae

The best weapon against thread algae is not a temporary solution, but is to set up the pond correctly from the beginning, below are some essential points that a correctly set up pond should meet:

  1. Pond substrate: A healthy pond bottom is crucial. A thick layer of pond substrate attracts beneficial bacteria that help purify the water and provides a stable base for plants.
  2. Oxygen plants: They purify the water, provide hiding places for fish and marine life, and help regulate temperature and algae growth.
  3. Water Lilies: These beautiful plants provide shade, help regulate water temperature and provide hiding places for fish.
  4. Marsh and aquatic plants: These plants play a crucial role in water purification and algae control.
  5. Pond Bacteria: These microorganisms are your pond's unseen heroes, contributing to a clear and healthy ecosystem.

Tip: Freshwater mussels are a great addition to a correctly designed pond, as they naturally purify pond water. One mussel purifies an average of 10 liters of water per hour.

Our step-by-step plan for a correctly set-up pond shows you step-by-step how to set up your pond correctly to prevent problems such as algae: Read our step-by-step plan.

Removing thread algae from the pond?

Is your pond already constructed and you are suffering from a filamentous algae infestation? Then try to restore the balance with good bacteria. These single-celled organisms ensure that string algae have less chance to grow. To combat filamentous algae with pond bacteria, use our in-house developed product: Bacta Clear. A product with a unique formula, consisting of two different strains of bacteria. When administering Bacta Clear, the bacteria attach themselves to the pond substrate. The enzymes secreted by the bacteria filter the water. In this way, the water in the pond returns to balance and the filamentous algae no longer have a chance to grow. By the way, most ponds are filled with tap water. Unfortunately, this does not succeed in controlling and removing string algae, because tap water contains a lot of lime and lacks the right bacteria.

Algae in the swimming pond or plant filter? Solution: place oxygen plants between the Sumpfpflanzen

Thread algae koi pond

Likewise, filamentous algae can occur in a koi pond. This is a deep pond built specifically for koi carp, in which they can overwinter well. One solution may be to feed the pond fish less, which prevents uneaten or undigested food from becoming a food source for the algae. In addition, you are more likely to have the koi carp eat the filamentous algae. A second good solution is additional planting of aquatic plants. This would specifically involve plants that filter well and add oxygen to the water. Simon's best choice of plants are the Lis, Lisdodde, Pikeweed and Japanese cave pipe. Controlling thread algae in the koi pond is not done with one plant. Feel free to place several aquatic plants in the pond. They will grow back on their own when the koi carp have eaten from them.

Others bought this to make their pond algae free



Other supplies for the pond

Aquatic plants category

Pond Plants

Pond substrate for your pond

Pond substrate

Water purifiers

Pond Plants

Pond Kits

Simon van der Velde

Pond Advice

Can't decide yet? Check out Simon's advice.

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Tips, advice and substantial savings
I would like to share my experience with you, and advise you to solve any pond problems and reduce pond maintenance. As a result, you can easily save hundreds of dollars.
Tips, advice and substantial savings
I would like to share my experience with you, and advise you to solve any pond problems and reduce pond maintenance. As a result, you can easily save hundreds of dollars.
Tips, advice and substantial savings
I would like to share my experience with you, and advise you to solve any pond problems and reduce pond maintenance. As a result, you can easily save hundreds of dollars.
Tips, advice and substantial savings
I would like to share my experience with you, and advise you to solve any pond problems and reduce pond maintenance. As a result, you can easily save hundreds of dollars.