Green Water: How Does Barley Straw Work to Prevent Algae?

Green Water: How Does Barley Straw Work to Prevent Algae?

Barley straw is a cheap and effective way of keeping a pond clear of algae the natural way. Barley straw is completely natural and safe, and will inhibit algae growth without any risk to wildlife or plants.

Barley straw or barley extract will slowly begin to decompose when added to your pond, or into your pond filtration system. As it decomposes the cellular structure of the barley begins to break down - the rate of breakdown is dependent on water temperature how well oxygenated the pond water is. In spring and summer, barley straw will work quickly (usually within 2 weeks) whereas in colder months it can take twice as long.

As barley straw decomposes, fungi develops, and the barley begins to rot. As it is rotting and fungi eat away at the remains of the barley, humic acid is produced, which is the first major step towards algae control. Humic acid reacts with oxygen in the water and sunlight, eventually transforming into hydrogen peroxide.

Hydrogen peroxide is a powerful algaecide, and will inhibit the growth of algae and blanketweed. When produced from barley straw bales it’s in a low enough concentration to be safe for fish and other established plants.

The effectiveness of barley straw depend on the amount of algae you have, and other factors like the ability for algae to proliferate faster than its broken down (in direct/excessive sunlight), the type of algae, and how well oxygenated the pond remains - especially during a hot spell.

There are many other methods of controlling and ridding algae that are considered more effective, although they are often more expensive and not organic. Using a UVC sterilizer in your filtration system is highly effective, as well as other methods of chemical and mechanical filtration. Barley straw is a biological way of dealing with pond algae, and should be seen more as a preventative rather than a quick fix to resolve green water or algae blooms.

barley straw in ponds

How to Treat the Pond with Barley Straw

Treating a pond with Barley Straw bales is simple and easy - all you need to do is throw them into the pond. As the barley straw breaks down and rots, it releases compounds which stop algae and blanket weed growth.


To browse our range of Barley Straw online click here.

Photo credit(s): Canva Pro Licence


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