Promote a healthier eco-system for your pond by giving it a double shot of Scottish Barley Bales, a technique which has been employed since the Middle Ages to naturally clear the water.
As far back as the middle ages it was recognized that by adding straw to wells the water was cleaner and free of growth. In more recent years, after allowing a bale of barley straw to stay in a pond where it had fallen, a farmer noted that there was much less string algae in the pond. The discovery prompted the Centre for Aquatic Plant Management in England to undertake studies which, in effect, confirmed that barley straw does have a beneficial effect in clearing water.