How to remove Duck Weed from a pond
What does it look like?
- Dead pond plants
- Excess pond cover by plants
- Little rounded leaves across the surface of the pond
- Oval/Round leafed plant covering water
- Plants blocking light
- Stagnant smell
What are the fish doing?
- Fish gasping / rapid gill movements
- Unexplained deaths
What should I do?
- Manually remove as much duckweed as possible
- Treat the cleared pond with your chosen treatment – as recommended below
- Encourage good plant growth by cutting away dead plants and adding good nutrients in plant food
- Create surface breaks or high areas of flow using a fountain/waterfall if duckweed is a persistent problem
- Treat with a Pond sludge treatment to eat dead plant matter and discourage further outbreaks
Why does this happen and how do I prevent it?
Duck Weed is a small leafed plant which will grow to carpet the surface of the pond . In extreme cases Duck Weed can grow so rapidly that it effectively smothers the pond, reducing oxygen and light levels, leading to dead fish and plants. There are several factors that can cause excessive growth of Duck Weed and although an effective treatment will kill the plant, the causative factors must be addressed to prevent further outbreaks.
Major influencing factors are :
- Excess sunlight so you may benefit from adding floating plants – e.g. Lily’s and water soldier – to cover up to 50% of the pond surface area or use planting around the pond to create areas of shade across your pond. You do not want to completely shade the pond as this will discourage good plant growth, however finding a balance could reduce the recurrence of Duck Weed
- More nutrients than your existing pond plants can use which stimulates algae growth. Nutrient levels can be controlled by encouraging plenty of healthy fast growing pond plants and regularly removing waste and sludge from the pond.
Always use a Pond Sludge buster after Algae control products to safely break down and remove dead algae
Other areas to consider to help prevent further outbreaks and aid treatment:
- Test water regularly (high nitrate levels will encourage algal blooms)
- Keeping plants healthy by feeding with Flora Boost
- Using Pond Sludge Buster or Bioactive Sludge Control once a month will help to reduce waste and remove nutrients from the water
If Duck Weed is becoming a frustrating and common problem in your pond you could consider using a pond filter which will help to remove excess nutrients and waste products like sludge. Using a filter with a fountain or waterfall may also be useful as Duck Weed is unlikely to grow in areas of water flow or where flow breaks the surface of the water.
Find out more…
What treatment should I use?
Blagdon Duckweed Buster
Blagdon Sludge Buster
Blagdon Clean Pond Pods - available in stores March 2020
For ponds without fish
Blagdon Wildlife Bioactive Sludge Control
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