A: More and more people are using barley straw as an all-natural (and duck friendly) way to control pond scum—and for good reason. Barley straw is a safe, natural alternative to manufactured chemicals and one of the compounds produced by submerged, decomposing barley straw may actually help keep your pond clear.
You need a lot of it to be effective.
In your quarter-acre pond, you'd need between 25 and 50 pounds (1 to 2 standard bales) of barley straw, depending on your pond's condition. That straw would then need to be broken up, divided among several permeable bags and placed around the perimeter of the pond with weights in water no deeper than 6 feet.
That's a lot of work!
And if you don't replace the barley straw as it decomposes, it just turns into more decaying organic debris in the pond.
So what are your options?
Focus on the quality and cleanliness of your pond. Reduce the decomposing plant matter, fish waste and other nutrients by adding a stout aeration system and wildlife-safe beneficial bacteria.
You can give barley straw a try or you may want to reconsider manufactured chemicals, like Algae Defense. The algaecide has no water use restrictions, and it's safe to use around ducks and other wildlife. And because it only needs to be used when algae growth is occurring, you could use it as a one-time algae bomb. Not all chemicals are bad!