General Information

This liquid copper sulfate product is easy and ready to use to control algae in slow-moving or quiescent bodies of water including: golf course, ornamental, fish, irrigation and fire ponds; fresh water lakes and fish hatcheries; water destined for drinking water and non-potable water reservoirs and associated waters (river, streams, bays and coves); and crop and noncrop irrigation conveyance systems (canals, laterals and ditches). Waters treated with COPPER-Z 4/4 may be used for swimming, fishing, drinking (after further treatment), livestock watering or irrigating turf, ornamental plants or crops.

COPPER-Z 4/4 effectively controls many species of both filamentous (mat forming green algae) and planktonic (single cell bluegreen) algae. The rate of copper sulfate and control are affected by algae species, water hardness, water temperature, amount of algae present, as well as whether water is clear, turbid, flowing, or static. Preferably water should be clear and above 60 DEGREES F, with treatment made in the late morning on a sunny day. Static water usually requires less copper sulfate than flowing water. The harder the water, the higher the required rate of copper sulfate. When mats of filamentous algae are floating, the surface of these mats should be sprayed. Algae will absorb the copper sulfate within hours after treatment, and death should be evident within 3 to 5 days. If there is some doubt about the concentration to apply, begin with a lower rate and increase the rate until the algae are killed. (A few algae species are resistant to copper sulfate treatment and may not be killed). Repeat treatments may be needed to keep algae under control to the desired levels.

Treatment of algae can result in oxygen loss from the water caused by the decay of dead algae. This loss can cause fish suffocation. To minimize this hazard, treat 1/3 to 1/2 of the water area in a single operation and wait 14 days between treatments. Begin treatments along the shore and proceed outwards in bands to allow fish to move into untreated water. Trout and other species of fish may be killed at application rates recommended on the label, especially in soft and acid waters.

Limitations, Restrictions, and Exceptions


When to apply: Early treatment is essential for most satisfactory algae control at the lowest rate levels. Early growth is usually confined to shallower shore areas. Begin treatment when not over 5 to 10% of the water surface area is covered with algae growths which is usually nearest

the shoreline. Delaying treatment until heavy algae growths are present usually requires a higher rate and may result in fish distress or death since rapid decomposition of heavy growths greatly reduces the oxygen content of the water. Several repeat treatments are necessary to control algae each season.

Rates to Control Algae: First, accurately determine the surface acres of water to be treated at one time and multiply this by the average depth in feet of this water area to determine the acre feet of water to be treated. [One acre foot = one surface acre (43,560 sq. ft.) x one foot depth.]

Each acre foot of water contains 326,000 gallons, or 2,720,000 pounds of water. 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.

To obtain the correct amount of Helena Copper-Z 4/4 divide 5.44 lbs. by 1.677 lbs. which equals 3.2 gallons of Copper-Z 4/4. The rates of Copper-Z 4/4 per acre foot of water to control specific algae species are given later in the label.

Secondly, if the problem algae genera is known, use the table below and its equivalence to determine the approximate rate of this product needed to control that genera. If the genera of either filamentous or planktonic algae is not known, apply 6.2 - 9.3 quarts of this product per acre foot of water, using the lower rate in soft water and the higher rate to hard water. For control of bottom-attached algae Chara and Nietella use 9.3 - 12.8 quarts per acre foot of water to be treated. If control is not achieved or in very adverse waters, a higher rate may be needed, but consider the fish species.


The genera of algae listed below are commonly found in waters of the United States. Use the lower recommended rate in soft waters (less than 50 ppm methyl orange alkalinity) and the higher concentration in hard water (above 50 ppm alkalinity). Always consult State Fish and Game Agency before applying this product in municipal water.


Fish Ponds and Fish Hatcheries (Aquaculture): Maximum treatment level is 0.4 ppm of metallic copper (2.8 gallons of COPPER-Z 4/4 per acre foot of water).

Restricted Entry Interval

48 hours