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Preventing pond algae

Find out which plants an aquatics expert recommends to prevent algae from taking over your garden pond.

Member question: 'What plants would you recommend for a small pond so the water doesn't go green?'

Add a mixture of plants

The aim is to out-compete algae for nutrients and light with other, more desirable plants.

Create shade

Dan Brain from Springs Aquatic

You should aim to shade 60% of the pond in the summer, using various plants.

Tall marginal plants, such as irises, are good for creating shade. Fast-growing oxygenators that use nutrients quickly in open water, such as hornwart or Lagarosiphon major (also known as Elodea crispa), are also important.

Water lilies are good for shading large areas of the surface. Make sure you choose a species suitable for the size of pond, remove and dead flowers and leaves throughout the summer and cut the plant back come winter.

Add an ultraviolet (UV) unit

Pond UV unit

If you have a pump and filter, installing a simple UV unit which kills algae cells is an effective way to keep your pond water clear.

Most filters now come with UV units as standard and only need a change of bulb each spring.


About our expert trader

Dan Brain from Springs Aquatic

Our expert: Dan Brain

Dan Brain is director at Which? Local-recommended Springs Aquatic, a pond maintenance business based in Eastleigh.

The business was established in 2008 and operates throughout the Hampshire region.

Read reviews for Springs Aquatic