Barley straw can be an effective treatment for the prevention of blanket weed pond scum, pond algae, but there are a few caveats and precautions to keep in mind. Barley straw pond algae control is not always the best method of pond algae control. Read the list of precautions, and decide for yourself. Instructions on the use of barley straw pond algae control, including the proper methods are given below.
Barley straw will not:
- Eliminate existing pond scum
- Work in muddy water
- Work in water with low oxygen
- Work only against bad pond algae production
Barley straw will:
- Decompose, adding nutrients to the water
- Use oxygen during decomposition
- Kill all forms of algae, including phytoplankton
Barley straw only works to prevent pond algae, not to kill it, and will not work in certain conditions like muddy water and low oxygen. It will decompose and use oxygen during the process which can be fatal to fish if too much decomposition occurs too quickly. Decomposition also produces nitrogen which can act as a fertilizer for future weeds and algae production, which will increase in the newly cleared water. Barley straw will decrease phytoplankton production resulting in water clarity, and a lack of food for fish as well as allowing sunlight to penetrate to the bottom, which can result in more pond algae and lake weed production after the barley is gone. A proper fertility program to promote the growth of phytoplankton should be put in place to prevent such an outcome. Once a good fertility program is in place and ongoing, the need for any pond algae treatment will evaporate in most cases.
With all of these possibilities in mind, this is the process you can use to apply barley straw to a pond or lake for the treatment of pond algae:
Amount of barley straw to use
If pond scum is a recurring problem, 100, to 250 pounds of barley straw per surface acres can be used for preventing unwanted lake algae. A surface acre, is 43,560 square feet. To determine the size of your pond or lakes surface area, multiply the number of feet from side to side, with the number of feet end to end. The numbers do not have to be precise, just as close as possible. If the ends or sides are not equal distances, simply average the distance of both sides, and the distance of both ends before multiplying. This should be close enough for a barley straw treatment.
How to apply barley straw
Separate the barley into equal units, and place it in weighted mesh bags, rolls of hardware cloth, or cages, and sink them around the pond. A string or rope tied to the bags and a stake will help in retrieval. 50 pound onion bags or gunny sacks work well, you can stuff about 6 to 8 pounds of barley straw in an onion bag or gunny sack.
Where to place barley straw
Barley straw will only be effective in oxygenated water, which limits placement to the edges and close to the surface, so do not submerge the straw more than a few inches below the surface or it will simply rot without producing the desired effect.
See also: Using Barley Straw As A Blanket Weed Treatment
and Barley Straw Pond Algae Treatment Drawbacks