Barley straw is a natural non-toxic, inexpensive inhibitor of floating algae in ponds and a stimulator of pond plants. Barley straw has been used in Europe for centuries for this purpose. It works by decomposing and releasing minute but continuous amounts of hydrogen peroxide. Decomposition of the barley straw in the presence of sunlight and oxygen produces the hydrogen peroxide needed for inhibition of new algae growth. Barley straw does not kill existing algae (which will die naturally in several weeks), but seems to prohibit growth of new algae.
Each package treats 500 - 1000 gallons (click Calculate to compute quantity needed to treat your pond). For existing clarity problems, use Mother Nature's Pond Clarifier in addition to the straw bags.

The barley straw should be added to your pond in early spring, one month before new algae is expected to appear. One application can inhibit the growth for 6 months. A new application should be applied after 5 months to ensure continuous protection. When applied to cold water (less than 50 degrees F), it may take 4 weeks or more for the straw to begin producing the active chemicals that inhibit algae growth. If the straw is applied to warmer water (above 70 degrees F), it may become effective faster. In any case, barley straw remains effective for approximately six months after application. If algae starts to grow on the bag, it is high time to replace it.

General recommendation is 8 oz. Per 1000 gallons of water or 8 oz per 100 sq. feet of surface area. The amount of straw to apply varies based on pond surface area as well as volume. Add required amount of straw in the spring and another application in 5 months. Less straw may be required for the second application if you have attained good results with the first application. In a pond with a history of algae problems, a higher initial amount may be warranted. For ponds under 800 gallons, 4 ounces of barley straw should be used. Click here to calculate how much barley is required for your pond.

It is best to anchor the straw packages with a rope to keep the straw near the surface of the pond where sunlight and oxygen are most prevalent and also for easy retrieval for replacement. Apply the straw at several locations around the pond, near a water source such as a waterfall or filter where the water can flow through it. Straw may be placed inside a non-pressurized filter or skimmer. Most algae production occurs in shallow water, so the bulk of the control compound needs to be located there.


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