Barley Straw Pond Treatment Instructions

When added to a pond, barley straw reduces algae and lessens suspended solids. Researchers know that the decomposing barley straw causes the effect, but they haven't singled out one chemical in this process that is responsible. Some say it is caused by the combined effort of the chemical constitutes. Other researchers think one chemical is involved.

Pond Treatment

For best results, put barley straw in the pond in April or after the last frost. This inhibits new algae from growing, rather than reducing existing algae. Ponds warm up in May, and the new algae grows rapidly unless treated with barley straw. You may add another treatment in July.


There are three kinds of barley straw products.

  • Barley straw bales
  • Barley straw pellets
  • Barley straw planters

The planters are made of barley straw so that you can place a plant inside before placing it in the pond. Put potting soil and fertilizer around the aquatic plant and soak the planter completely before placing it in the pond.

Some of the barley straw products come with a netting to hold it. The bales have cork floats to stop them from sinking.

The instructions on a package will tell you how much to add per gallon of water in the pond, and some instruct according to pond size.


Barley straw doesn't harm fish, waterfowl, pond fish or people. No harmful effects have not been documented during research.

Besides stopping the new growth of pond algae, barley straw also encourages invertebrates to eat contaminates that would otherwise harm the pond.

Other Barley Straw Facts

Barley straw will work if it is put in late in the season, but it will take longer to work. Algae is always in the cycling and aging process, so once established, it is harder to remove.

The barley straw will take 2 to 6 weeks to start working. The kind of algae in the pond determines how long it takes to be active; for example, string algae lives longer and is harder to remove.

For best results, add a device to your pond that will cause the water to move, like:

  • Skimmer box
  • Filter falls
  • Filter box
  • Waterfalls base

The more suspended solids in the pond, the longer the barley straw takes to work. These solids will coat the barley.

The rate of removal depends on what is already in the pond, the temperature and the total surface space of the pond. In a pond temperature of 40 degrees, the barley straw will take 2 weeks to work. In water over 40 degrees, results will begin sooner.

The most effective spot to place the barley straw is where a high volume of water can flow through it.

For best results, the straw should be looser, not compacted. It needs to be well-oxygenated well and get sufficient sunlight.

The type of barley straw doesn't increase or diminish the results. Domestic and imported varieties are available.