Barley straw is one of the oldest tools used in pond management and many people use it for a form of natural pond algae control. Several university studies have tested it's effects on maintaining a clearer pond and the results have showed promise. Today there are a variety of products from actual baled straw, to barley pellets.
It's our opinion, and studies confirm that barley is best used as a preventative to new growth and does not always serve as an effective treatment to existing issues, however personal evidence and experiences from pond owners have indicated that it may work to improve a pond's clarity. With this in mind, and by the fact that it's very safe and natural, it's often worth a try for improving a small pond.
Barley, as it decays, releases an element that's toxic to algae. It can work well with beneficial bacteria, ultraviolet filtration and other common algae control devices.
If you've tried just about everything else but haven't given barley straw a try, give it a shot, it's worked for many happy pond owners.
The baled product below is best used for small ponds. Use the pellets in larger ponds and lakes.