If there is something wrong with your fish; they look ill or are dying, or there are water quality problems, we strongly advise that you test your pond water.

Use the images and descriptions below to determine what's wrong, then click through for treatment advice.

How to treat High Nitrate in a pond

What does it look like?

High nitrate test results
Invisible issue

What are the fish doing?

No obvious behaviour symptoms - exetreme levels may cause gasping and rapid gill movement.

A hand pouring a clear liquid Blagdon Treatment into a bucket of pond water

What should I do?

High Nitrate can be caused by excess waste materials, so use a sludge treatment to break down waste and remove it from your pond.
Increase nitrifying bacteria by using Bio Start or Bioactive Activator which will boot the pond's biological filtration

See which treatments we recommend >

Why does this happen and how do I prevent it?

Nitrate is a naturally occurring chemical in your aquarium and is created by the breakdown of Nitrite by bacteria in your pond as part of the Nitrogen cycle. Nitrate can also be introduced into an aquarium through the tap water you use.

To help prevent high nitrate:

Encourage healthy plant growth which will use the nitrate as a food source – regularly feeding your plants will help to reduce excess nutrients
Maintain a healthy pond by reducing waste and sludge and encouraging healthy bacteria to grow using a Bio Start product.
Carry out water changes – first check that your tap water does not contain Nitrate.-

If you are keeping a pond with fish, we would recommend using a filter to help create a healthy environment for your fish and wildlife. Mechanical filtration will remove physical waste matter, whilst the Biological Filter will break down the chemicals released by waste through the Nitrogen cycle. Filters have the media needed to harbour and mature a strong biological filter to reduce water quality problems.

What treatment should I use?

Blagdon Clean Pond Pods - available in stores March 2020

Clean Pond Pods are an all in one, easy dose treatment - ready to use with no measuring required that tackle the most common and frustrating pond problems.

Find out more >

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Blagdon Sludge Buster

Sludge Buster contains cultures of biological organisms which, actively consume dead algae and organic sludge without deoxygenating the pond, this takes the hard work out of keeping your pond clean and healthy.

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For ponds without fish

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and

Blagdon Wildlife Bioactive Sludge Control

Wildlife Bioactive Sludge Control reduces filter cleaning, reduces pond silt and water clouding and reduces the chances of pond oxygen problems. The natural harmless bacteria consume organic waste for a cleaner, healthier pond.

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Blagdon Bio Start

Bio Start contains biological cultures which within hours begin to set up the essential cycles that ensure pond water is safe for fish. Each sachet contains 8,500 million bacteria to consume fish waste.

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Liquid and for ponds without fish

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Blagdon Wildlife Bio-activator

Wildlife Bio-Activator stimulates ongoing breakdown of toxic waste produced by fish and wildlife. This treatment will help to establish an essential biological cycle in new and cleaned out ponds.

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Use with any of the above

Blagdon Flora Boost

The Flora Boost formulation excludes nitrates and phosphates that would otherwise stimulate algae growth, instead it supplies the essential micro and macro nutrients necessary for pond plant growth and encourages flowering species to bloom...

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Not what you are looking for? Back to Diagnose What's Wrong >

If there is something wrong with your fish; they look ill or are dying, or there are water quality problems, we strongly advise that you test your pond water.

Use the images and descriptions below to determine what's wrong, then click through for treatment advice.

How to treat High Nitrate in a pond

What does it look like?

What are the fish doing?

What should I do?

See which treatments we recommend >

Why does this happen and how do I prevent it?

What treatment should I use?

Blagdon Clean Pond Pods - available in stores March 2020

Blagdon Sludge Buster

Blagdon Wildlife Bioactive Sludge Control

Blagdon Bio Start

Blagdon Wildlife Bio-activator

Use with any of the above

Blagdon Flora Boost

Treatment dosage Calculator

Testing your pond water

Seasonal pond maintenance

Understanding Your Pond

Understanding Fish Sickness and Stress in the Pond

Understanding the Pond Environment

Why Should I use Pond Guardian Salt in my Pond?

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If there is something wrong with your fish; they look ill or are dying, or there are water quality problems, we strongly advise that you test your pond water.Use the images and descriptions below to determine what's wrong, then click through for treatment advice.

How to treat High Nitrate in a pond

What does it look like?

What are the fish doing?

What should I do?

See which treatments we recommend >

Why does this happen and how do I prevent it?

What treatment should I use?

Blagdon Clean Pond Pods - available in stores March 2020

Blagdon Sludge Buster

Blagdon Wildlife Bioactive Sludge Control

Blagdon Bio Start

Blagdon Wildlife Bio-activator

Use with any of the above

Blagdon Flora Boost

Treatment dosage Calculator

Testing your pond water

Seasonal pond maintenance

Understanding Your Pond

Understanding Fish Sickness and Stress in the Pond

Understanding the Pond Environment

Why Should I use Pond Guardian Salt in my Pond?

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If there is something wrong with your fish; they look ill or are dying, or there are water quality problems, we strongly advise that you test your pond water.

Use the images and descriptions below to determine what's wrong, then click through for treatment advice.