Algae Control in
Stock Tanks and Ponds
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Algae Control in |
Chlorine Bleach
Add 2-3 ounces of 5.25% sodium hypochlorite (unscented laundry bleach) per 100 gallons of
tank capacity every week. The chlorine will dissipate more rapidly in hot weather or if
organic material is present in the tank. Do not use pipeline sanitizer or swimming pool
chlorine. To determine gallonage of a square or rectangular tank, multiply in feet:
(length x width x depth x 7.5). To estimate gallonage of a round tank, multiply in feet:
(diameter x diameter x depth x 6).
Copper Sulfate
Add copper sulphate (Bluestone or Blue Vitrol) at the rate of 1/8 teaspoon per 100 gallons
of water to kill existing algae. It should then be mechanically removed. Cover or shade
the tanks to help slow algae growth.
Zinc Sulfate
Dissolve one cup of zinc sulfate in one gallon of warm water and put 1/2 cup of this
solution per 100 gallons of water in tanks as often as necessary (it will depend on number
of animals drinking, amount of organic material in trough, and weather). Or if bird manure
on the roof is not a factor, direct runoff from galvanized roofs into waterers.
Goldfish
Add 4-6 goldfish per 100 gallons of tank capacity. Water temperature should be at least
60°F for best fish survival, so spring-fed waterers or tanks with a constant water
turnover may have inconsistent algae control. Remember you're trading the presence of
algae for the presence of fish feces. Take the goldfish inside the house before fall frost
and put them back out again in summer.
Ponds and Lakes
Copper Sulfate
Apply copper sulfate crystals at a rate of 2-3 lbs. per acre-foot of water. An acre-foot
is 43,560 square feet in area x 1 foot deep. Put the crystals in a porous bag and drag it
through the water until the crystals dissolve. Use an empty milk jug as a float to keep
the bag near the surface. Apply in early spring prior to formation of matted growth.
Chemical treatment works best when the water temperature is between 60°F and 80°F and
algae clumps are broken up during chemical application. Avoid treating when the water
temperature is above 80°F and treat only 1/4 to 1/3 of the vegetation at a time to
prevent oxygen depletion and a possible fish kill.
More information on aquatic weed control can be found at http://mdc.mo.gov/landwater-care/plant-management/aquatic-plant-management/controlling-nuisance-aquatic-plants/nuisan-0 and http://mdc4.mdc.mo.gov/applications/MDCLibrary/MDCLibrary2.aspx?NodeID=2495
Barley Straw
Apply barley straw to the water surface at a rate of 225 lbs. per surface acre
in early-to-mid April for Missouri. Spread the straw over the areas of algae growth. The straw, when it
decomposes, produces an anti-algae agent. The effective chemical compound is produced only
when the straw decomposes in the presence of oxygen, so tightly-packed bales which can
become anaerobic are not the best method for application. It may take about a month to
begin control, which lasts up to six months depending on various factors such as
temperature and initial algae concentration. The barley straw is less effective on ponds
with high nutrient concentrations.
More information on algae control using barley straw can be found at http://www.btny.purdue.edu/pubs/APM/APM-1-W.pdf
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Webpage maintained by: Bob Schultheis Natural Resource Engineering Specialist Email comments to: schultheisr@missouri.edu Last revised: 07/15/2011 |
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