An algaecide or algicide is a substance used for killing and preventing the growth of algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

.

Natural algicides

Barley

Barley

Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...

 straw

Straw

Straw is an agricultural by-product, the dry stalks of cereal plants, after the grain and chaff have been removed. Straw makes up about half of the yield of cereal crops such as barley, oats, rice, rye and wheat. It has many uses, including fuel, livestock bedding and fodder, thatching and...

, in England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, is placed in mesh bags and floated in fish pond

Fish pond

A fish pond, or fishpond, is a controlled pond, artificial lake, or reservoir that is stocked with fish and is used in aquaculture for fish farming, or is used for recreational fishing or for ornamental purposes...

s or water garden

Water garden

Water gardens, also known as aquatic gardens, are a type of man-made water feature. A water garden is defined as any interior or exterior landscape or architectural element whose primarily purpose is to house, display, or propagate a particular species or variety of aquatic plant...

s to help reduce algal growth without harming pond plants and animals. Barley straw has not been approved by the United States Environmental Protection Agency

United States Environmental Protection Agency

The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

 (EPA) for use as a pesticide and its effectiveness as an algaecide in ponds has produced mixed results during university testing in the US and England

Synthetic algicides

Synthetic algicides include Copper sulphate, which is very toxic, and Polyquat

Polyquat

Polyquat is the common name for a class of swimming pool and hot tub algaecide which is chemically mostly n-alkyl-dimethyl benzyl ammonium chloride , which is also known as benzalkonium chloride. The alkyl groups are usually C14 and C16...

.

External links

• National Pesticide Information Center (NPIC) Information about pesticide-related topics.