Barley straw is no magic bullet to rid your decorative pond of unsightly discoloration. But when used as a preventive measure, barley straw offers pond owners an attractive option to chemical products to manage water quality issues.
The Science Behind Barley
Barley straw has been widely used for decades to control water quality issues in many bodies of water, including large reservoirs and canals. Researchers have yet to precisely pinpoint how it works, but generally, it's believed that as barley decomposes the by-product released may protect from future issues. It has not been found to harm fish, waterfowl, or pond inhabitants in any way and, in fact, some studies suggest the straw benefits fish.
Using It in Your Pond: Science aside, what's important to pond keepers is how to use it in their ponds. Currently, hobbyists can choose from three different types of barley products: barley straw in bale form, barley pellets, and barley extract.
Barley Straw Bales
Typically available loose in a mesh bag, barley straw bales and planters should be placed in the pond early in the season (around March or April, depending on your climate) as the straw must start to decompose before it releases it's beneficial substances. One pound of barley straw will treat a 100-square foot pond for approximately four-to-six months. Bales do tend to become messy and may contribute to algae problems if large amounts remain floating in the pond so be sure to keep the straw well-aerated, and contained in near your waterfall, stream or in shallow water, if possible.
Compressed into a compact form, the barley pellets also contain all the beneficial substances found in barley straw without the unsightly look of bales, pillows or pads. They're designed to break down quickly and produce phosphate-combating humic substances. The pellets may also buffer pH and control alkalinity in your pond. A 6-pound bag will treat an 800-gallon pond for up to six months, while a 12-pound bag will treat a 1,600-gallon pond for up to six months.
Also offering the benefits of barley straw without the mess or unsightly bale floating in your pond, barley extract contains only the beneficial by-product in liquid form. Because you don't have to wait for the barley straw to decompose, it also acts faster than pellets and starts to work on contact. An 8-ounce container treats up to 4,000 gallons for three months; a 16-ounce bottle treats up to 8,000 gallons for three months.
Your best defense against algae has always been a good offense. Keeping your pond clean and balanced with adequate filtration, bacteria treatments, minimal fish loads and sun exposure will reduce your dependence and need for additional treatments in general.