Copper Sulfate for Algae Control

Let Your Lake or Pond Shine by Using Copper Sulfate to Kill Algae

LAKES, POTABLE WATER RESERVOIRS, PONDS (Golf, Farm, Fish and Fire), FISH HATCHERIES, AND CROP AND NON-CROP IRRIGATION CONVEYANCE SYSTEMS, DITCHES, CANALS AND LATERALS: Copper Sulfate kills filamentous and planktonic algae in water.

Apply at a rate of 3 to 6 pounds per acre foot of water (0.27 ppm to 0.54 ppm copper in the treated water). Apply as a uniform surface spray dissolved in at least 3 to 5 gallons of water using boat, plane or other pressurized spray device. Apply twice yearly or as needed. Determine the number of acre feet of water to be treated.

An acre foot of water is equal to one acre of water one foot deep which equals 328,000 gallons or 2,720,000 pounds.  An acre foot can also be defined as an area of water 660 feet X 66 feet X 1 foot depth.

How to Apply: Copper Sulfate can be applied to impounded water by the following methods:

1. Application by Dragging Under Water: By placing Copper Sulfate in a burlap or finer mesh bag, apply by dragging the bag attached to a boat or float so that bags are suspended in the top foot of water until the crystals are dissolved. Drag the bag of copper sulfate first near the shoreline and continue outward by moving as the boat travels in parallel lines about 20 to 100 feet apart until area has been treated or until 1/3to 1/2 of the surface area has been treated. Continue dragging bag over treated area until the required minimum dose is applied and all copper sulfate is dissolved. Determine the quantity of copper sulfate needed to treat the problem area following directions and precautions on the label.

2. Application by Spraying Solution on Water Surface: Dissolve the minimum required dose of  Copper Sulfate in water and spray the solution uniformly over the body of water. When spraying a solution of copper sulfate, mix copper sulfate in sufficient water to thoroughly spray the water surface. While the volume per surface acre depends on the type of spray equipment being used, spray volume should be approximately 20 to 500 or more gallons per acre of surface water. Several types of solutions and spraying equipment may be used. Observe previous cautions on the effect of copper sulfate solution on various metals in spraying containers.

3. Application by Slug Method: Make a dump of Copper Sulfate into the irrigation ditch or lateral at ¼ to 2 pounds per second of water per treatment. Repeat about every 2 weeks as needed. A dump is usually necessary every 5 to 30 miles depending on water hardness, alkalinity, and algae concentration. Copper Sulfate becomes less effective as the bicarbonate alkalinity increases. Its effectiveness is significantly reduced when the bicarbonate alkalinity exceeds about 150 ppm as calcium carbonate (CaCO3).

4. Application by Broadcasting: Dry Copper Sulfate can be broadcast on the water surface using a properly equipped boat. An air blower can be used to discharge these crystals at a specific rate over the surface of the water. When using this method, the wind direction is an important factor. Do not use this method unless completely familiar with this type of application.

5. Application by Spraying from Airplanes and Helicopters: Professional personnel licensed by the State Agricultural Extension Service are allowed to apply dry Copper Sulfate in some states. Rate may not exceed 6 pounds per acre foot of water.

6. Application by Injection in Water: A solution can be made with Copper Sulfate that can be injected in the water via a piping system.

CROP AND NON-CROP IRRIGATION CONVEYANCE SYSTEMS, DITCHES, CANALS AND LATERALS: Copper Sulfate Crystals control the Potamogeton pondweeds, leafy and sago.

How to Apply: Copper Sulfate can be applied to irrigation conveyance systems by the following methods:

1. Continuous Application Method: Using a continuous feeder, apply 1.6 to 2.4 pounds per cubic foot per second per day. These rates will produce 0.074 to 0.11 ppm copper in the treated water.

Note: For best control of leafy and sago pondweed, it is essential to begin copper sulfate additions when water is first turned into the system or ditch to be treated and continue throughout the irrigation season. Copper sulfate becomes less effective as the bicarbonate alkalinity increases. Its effectiveness is significantly reduced when the bicarbonate alkalinity exceeds about 150 ppm as calcium carbonate (CaCO3). Should copper sulfate fail to control pondweeds satisfactorily, it may be necessary to either treat the ditch with a suitable approved herbicide or use mechanical means to remove excess growth. In either case, resume copper sulfate addition as soon as possible.

CONTROL OF ALGAE AND BACTERIAL ODOR IN WATERSCAPES, DECORATIVE POOLS, AND FOUNTAINS (Except California):

Apply in the spring or early summer when algae and bacteria first appear. The dosages are variable and depend upon algae/bacteria species, water hardness, water temperature, amount of algae and bacteria present as well as whether the water is clear, turbid, flowing or static. Preferably, the water should be clear with temperatures above 60º F. Higher dosages are required at lower water temperatures, higher algae and bacteria concentrations and for hard waters. For each 7,500 gals. of water, dissolve ¼ lb. Copper Sulfate  in one gallon of water. Pour the solution into the water to be treated. Several application points speed up dispersal. Static water requires less chemical than does flowing water. If uncertain about the dosage, begin with a lower does and increase until control is achieved or until the maximum allowable level of copper has been reached.

CONTROL OF ALGAE AND BACTERIAL ODOR IN SWIMMING POOLS (Except California):

Apply 1 to 2 lbs. of Copper Sulfate Crystal per 60,000 gals. (8,000 cu. ft.) of water. This will result in a concentration of 0.5 to 1.0 ppm of dissolved copper. Dissolve the required amount of copper sulfate in a plastic container and pour the solution into the pool. Use the higher rate where visible algae are present. For maintenance dosages, use the lower rate. Repeat the lower rate to control the recurrence of algae and avoid the buildup of copper. Copper Sulfate may be used to help control pool odors and algae during the winter months. Apply the higher rate while the pool is not being used during the winter. Treated pool effluent should not be discharged where it will drain into lakes, streams, ponds, or public water.

CALCULATIONS FOR THE AMOUNT OF WATER IMPOUNDED AND FOR THE AMOUNT OF COPPER SULFATE TO BE USED IN IMPOUNDED AND FLOWING WATER

Calculate water volume as follows:

1. Obtain surface area by measuring regular shaped ponds or mapping of irregular ponds or by reference to previously recorded engineering data or maps.

2. Calculate average depth by sounding in a regular pattern and taking the mean of these readings or by reference to previously obtained data.

3. Multiply surface area in feet by average depth in feet to obtain cubic feet of water volume.

4. Multiply surface area in acres by average depth in feet to obtain total acre-feet of water volume.

Calculate weight of water to be treated as follows:

1. Multiply the volume in cubic feet by 62.44 to obtain total pounds of water, or

2. Multiply the volume in acre feet by 2,720,000 to obtain pounds of water

Calculations of active ingredient to be added:

To calculate the amount of Copper Sulfate needed to achieve the recommended concentration

Multiply the weight of water by the recommended concentration of Copper Sulfate. Since recommended concentrations are normally given in parts per million (ppm), it will first be necessary to convert the value in parts per million to a decimal equivalent. For example, 2 ppm is the same as 0.000002 when used in this calculation. Therefore, to calculate the amount of Copper Sulfate Pentahydrate to treat 1 acre-foot of water with 2 ppm Copper Sulfate, the calculation would be as follows: 0.000002 x 2,720,000 = 5.44 lbs. Copper Sulfate Pentahydrate.

Calculation of water flow in ditches, streams, and irrigation systems:

The amount of water flow in cubic feet per second is found by means of a weir or other measuring device.

NOTE: If treated water is to be used as potable water (after further treatment), the residual metallic copper content must not exceed 1.0 ppm (4 ppm copper sulfate pentahydrate).

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