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Practical Application Of Barley Straw For String Algae & Murky Water Control

Turning Theory Into Practice

Now we are acquainted with the theory lets understand what has to be done to make the theory work and get rid of that blanketweed or string algae. Barley straw is the best type of straw to use it appears.

Before getting too excited barley straw is no quick fix and patience is required along with a dab of perseverance. At least you can get stuck in with confidence though.

Not all straws seem to work well and barley straw is definitely preferred, Maize, lavender, wheat, and linseed also work as substitutes ... for my money though I would use barley straw especially since the time period for success can be weeks even months. There is no point in trying second best under these circumstances. Barley hay or still green straw must not be used since this will tend to pollute the water rather than decay beneficially as required by virtue of the "still fresh" organic nutrients that could make matters worse for you and better for the algae.

How Long Will It Take To Get Rid Of String Algae?

Based upon evidence suspended algae forms succumb within about 6 to 8 weeks after placing the straw into position. However filamentous or string algae (blanketweed) control seems to take considerably longer and may even take more than a full season (Spring through Winter), unless treatment is started very early in the year. However bear in mind if the water is too cold the activity of breaking down the straw is very slow. Nevertheless treatment should certainly be started early and before the algae gets a good start. Remember that the action of barley straw is to prevent rather than kill algae growth.

Barley Straw Activity Needs Oxygen To Work & Clear String Algae

Here I go again. The rotting of barley straw to create the algae interruption process can only take place in the presence of well-aerated water. Failure to have sufficient oxygen will produce undesirable chemicals and not the traces of hydrogen peroxide we seek.

  1. For this reason the straw must also be placed into the pond in the right place and in the right form.

  2. The straw should be loose not firmly packed so that water/oxygen/straw contact takes place continuously.

  3. The straw should be placed where maximum aeration takes place ... close to the waterfall for example or the fountain.

  4. Since sunlight is required and most algae activity is in the upper levels of the pond the straw must float at ALL times ... this means artificial floatant devices are required since left to its own resources rotting straw will sink.

  5. In practice the straw should be placed into a very loosely packed net inside of which some expandable polystyrene or similar foamed material should be placed to create buoyancy ... small air-filled plastic bottles make good floating aids.

  6. To keep the straw in the ideal place anchor it with a weight tied to a length of fishing line or something similar.

  7. The presence of mud in the water will inactivate the important chemicals so do the best possible to remove mud precipitants. In cases where this is difficult to control then increasing the amount of straw is important.

Impact Upon Other Plants

No undesirable effects on plants, fish or any other life has been observed. In fact quite the opposite has been reported. As algae growth diminished and other plant life improved this, in turn, created better conditions for insects and small crustaceans ... in fact the whole food chain showed benefits.

How Much Straw Is Needed Starting With A Clear Pond Early In Spring?

  • Algae grows near the surface where the sun shines brightest. As such it is the surface area of the pond that determines the amount of straw needed and not the volume or mass of water in the system. Dr Newman determined the following application rates for ponds:

  • Initial Application ... 50 gms of straw per sq metre of surface (about 2 ozs per 10 square feet). In muddy water double this level.

  • It is better to over-use the straw than under-use but within reason bearing in mind the oxygen requirement and that you need to prevent anaerobic conditions.

  • Additional Applications ... Reduce by a half until a level equal to about 10 gms per sq metre (half an ounce per sq, yard) is reached to maintain ongoing control. Any re-appearance of algae should result in increasing the dosage to previously successful levels.

  • Beware Dense Algae Blooms and Hot Weather ... Both of these conditions are bad for oxygen levels in water as described in detail earlier. Avoid using barley straw under these circumstances unless extra air is in use.

  • Adding Fresh Straw ... Do not go and immediately replace old straw with new ... rather add new straw some weeks before it is time to throw out the old straw. In this way continuous biological activity is maintained and the algae will not so easily regain a foothold. Remember the algae is under control ... it has not disappeared.

  • Take note as mentioned in the beginning that at higher temperatures the straw would not last as long as in colder water. Make an assumption that it will take about 1 month for activity to start.

  • It will not help to place straw on pads of blanketweed or string algae floating on the surface. The blanketweed must be removed first. Keep removing it regularly to maintain effective hydrogen peroxide levels in the water.

Barley Straw Is NOT A Short Term Fix To Cure Blanketweed or String Algae Problems

A 4 year experiment on a full scale pond is underway in an English village (Wellbourn in Lincolnshire). The pond is known as The Beck and has been an eyesore for years. I contacted one of the village residents to ask about the experiment and here is Rod Storer's reply. "What a surprise to get your message. Yes the Barley straw programme has been going now for three years and I am convinced that it helps. Our village pond has a high nitrogen content, consequently the blanket weed infestation was severe. I string a line of "sausages" of straw wrapped in silage wrapping net along a rope across the pond each spring and it seems to be progressively suppressing the algal growth, does not eradicate it but reduces it and this year (third treatment year) the annual growth has been markedly less."

I gained my info on the subject from the Aquatic Research Project at Reading.

If you have reached the stage where you believe you want to understand the whole process of pond filtration then go through these articles in the order presented.


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