Barley Straw: How does it tackle Algae?
Barley straw contains natural compounds that inhibit the growth of algae. When barley straw decomposes in water, it releases certain chemicals that prevent the formation of algae colonies. This process is known as allelopathy, where the released compounds suppress the growth of other plants, including algae.
Specifically, here’s how Barley Straw in Ponds works:
Decomposition: When barley straw is placed in a pond, it slowly begins to decompose. The rate of breakdown depends on water temperature and oxygen content. Warmer temperatures and well-aerated conditions lead to faster decomposition. Barley straw isn't a quick fix for algae, because of the time it takes to break down.
Humic Acid Production: As the barley straw decomposes, it produces humic acid. This acid plays a crucial role in inhibiting pond algae growth.
Algae Control: The humic acid released from the decomposing barley straw interferes with algae development. It prevents the formation of algae colonies, helping to keep the pond water clearer and healthier.
Barley straw works best as a preventive measure in high-oxygen, well-aerated, and algae-free ponds. While it doesn’t kill existing algae, it helps inhibit new growth and contributes to long-term algae control.
Is Barley Straw the best method for tackling algae in a pond?
In fact, in most cases of algae growth, it is recommended to try mechanical removal and a pond clean-up before adding barley straw to the system. Having large amounts of algae usually indicates excess nutrients, excess waste, or low-aerated conditions. Adding more organic material to the pond, such as barley, would only make the problem worse as it takes a while to become effective.
In addition, as barley straw is reliant on the beneficial bacteria in your pond to break it down, adding it to low oxygen and high waste systems will actually reduce its effectiveness, as bacteria are likely already struggling with the low oxygen content and large bio-load present already.
Barley Straw Vs Barley Extract (Liquid) – Which is better?
When looking to purchase barley for ponds, you’ll likely come across two different products – barley straw and barley straw extract. Barley straw extract is a liquid formula which is more concentrated and faster to act compared to physical straw. Both of these work in a very similar way to prevent algae, but the delivery method is different, as well as the speed of action.
In general, barley straw is considered more “natural” and works slower against algae as there is less surface area for bacteria to break down the material. The straw would first need to go through multiple steps of decomposition before hydrogen peroxide is produced. This process can take anywhere from 3 weeks to many months, depending on water temperature and pond conditions.
Barley straw extract, on the other hand, comes in a highly concentrated liquid form and has been optimised for quicker turnaround. After you apply barley extract to the pond, beneficial bacteria will begin breaking it down much faster as it’s already optimised, leading to faster results. The main drawback of using extract over straw is that you need to be very careful with dosing, as the concentrated nature can make it very dangerous for pond fish. It is also more expensive than physical straw, and some treatments may contain additional chemicals to enhance it’s effects and increase its longevity.
Both barley straw and barley liquid extract work similarly against algae, but since you should not be using barley as a “quick fix” we’d usually recommend trying the cheaper and more natural physical straw. It may take longer to work, but it’s more cost effective and you’ll need to dose less as it releases substances into your pond at a more gradual rate compared to liquid formulas.
How to use Pond Barley Straw for Clear Pond Water
Barley straw will only work while decomposing under well oxygenated conditions, and should be left as close to the surface water as possible (floating or shallow shelf) for the best results in your ponds. It needs to be close to the surface so enough UV light from the sun can penetrate to form oxygen free radicals that eventually end up as dissolved hydrogen peroxide – the algaecide.
To work best barley straw treatment needs 3 things:
- Plenty of dissolved oxygen & aeration
- Be placed close to the surface for sunlight exposure
- Good water quality and bio-filtration (bacteria) for decomposition
When applying barley straw you want to make sure you have a stable aeration source, such as a fountain or air pump as well as a filtration system to help remove some of the ammonia and nitrites that come with decomposition. If your barley treatment sinks, you’ll want to remove it and place it on a shallow shelf or consider a lighter product.
Dosage in your pond should be per manufacturers guidelines, so you’ll need to read the instructions on the individual product you purchase. Never use more than is recommended as this will place unnecessary stress on your biological filtration, with very little in turns of extra algae removal. If you have liquid barley extract, you should also dose as per the label guidelines. Dissolved extract has the advantage of remaining free-swimming and being in constant sunlight, and you should see results faster in comparison with barley straw.
How long does barley straw take to work in ponds?
Depending on the type of barley straw product you’re using, the quality of your filtration, and how much aeration you have in place in your pond the full decomposition process usually starts within a few weeks and lasts between between 3 to 6 months. In warmer months decomposition will happen faster, and in colder months it will be a much slower process.
This is because beneficial aerobic bacteria work more efficiently in summer and much slower in winter when the pond water temperature drops. Hydrogen peroxide will continue to be produced throughout the entire decomposition process, and will gradually leech into water over this period to tackle algae. You should start seeing results from physical barley straw from 2-6 weeks if treated in spring/summer, and 6-8 weeks if treated in autumn/winter.
For barley liquid treatments, results will usually be slighter quicker and the concentration of hydrogen peroxide slightly higher. On average, you should start seeing results in your pond within 2-4 weeks during warmer months and 4-6 weeks in colder months.
Remember, barley straw is a preventive method of algae control, not an algae killer, so a good result from barley treatment would be less algae returning the following year. To remove large algae blooms, always use a direct treatment method and only use barley to supplement the process.
How often should you replace the straw in the pond?
For the best results and algae prevention, adding more barley straw a few times a year is good practice to make sure there is always a low concentration of hydrogen peroxide in the pond water. To ensure there is always a little barley decomposing and producing hydrogen peroxide, we recommend replacing your straw every 4 to 6 months.
To browse our range of barley straw treatments for ponds and aquariums please click here.
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