Coptrol FAQ

Coptrol FAQ

Coptrol can be used in a wide range of aquatic situations, including agriculture, potable water supplies, ornamental water storages and various mining, commercial and industrial environments.

Please review the list of Frequently Asked Questions below. If you have further questions please feel free to contact our Sales Team.

Technical Questions

Coptrol is a water-soluble chelated copper compound using proprietary organic chelating agents to target various types of algae with copper.

Algae seeks out Coptrol for its nutrient value and absorbs it through the cell wall. Coptrol is broken down by cell metabolism, releasing copper within the cell.

Most types of blue-green algae, including all free-floating and filamentous green algae. See Coptrol Aquatic Algaecide for more information.

The disadvantages and limitations of copper sulphate (bluestone) as an algaecide have been well documented.  (Please also note: “copper sulphate” and “copper sulfate” are alternative spellings of the same compound).

The natural “copper demand” of water bodies varies widely (Toth, 1968). This “copper demand” is made up by carbonate hardness which precipitates copper from copper sulphate (Bartsch, 1954) and further, by humic substances present in the water with complex copper derived from copper sulphate, thus reducing its toxicity to algae (McKnight, 1981).

Moore (1984) also notes that most species of algae excrete complexing ligands which themselves limit the efficacy of (unchelated) copper ions.

In 1960, Kessler concluded that trial and error methods were required on a pond‑by‑pond basis to determine the correct mode and level of treatment using copper sulphate algaecides.

The inherent disadvantages of copper sulphate for algae control have led to the development of Coptrol. Coptrol is a chelated copper* compound created using organic chelating agents.

Chelated copper has been shown to be more efficacious than copper sulphate in the control of algae.

Advantages are:

  • Lower concentrations of copper are required for the same result.
  • Application rates are less critical than bluestone.
  • Copper persistence in the water at an algae toxic levels is longer.
  • Treated water with Coptrol can be used for irrigation and potable water. Water treated with bluestone cannot be used in irrigation or drinking (potable) water.

Safety & Suitability Questions

Some fish and crustaceans species may be sensitive to Coptrol in low water hardness environments. Please check label for more instructions.

Coptrol is safe to use in ornamental ponds when used according to label directions.

Copper in any soluble form is potentially toxic to fish and crustaceans, therefore extreme care should always be exercised in ensuring directions are accurately followed. When Coptrol is used, protection from copper toxicity is provided where water hardness is more than 50 ppm (50 mg/litre expressed as calcium carbonate). Below a level of 50 ppm of hardness, copper in a toxic form may be liberated, thus harming fish and crustaceans.

Where fish are a valuable resource, it is important to test the water for hardness, and then to test Coptrol application on a few fish before applying Coptrol to the main fish biomass. If water hardness is below 50 ppm, Coptrol should not be used in the presence of valuable fish and crustaceans.

The alkaloid in Ragwort weed (Seneca jacobaea), which is toxic to horses and cattle, does not affect sheep which often graze on the weed. However, the Ragwort alkaloid reduces the sheeps’ ability to excrete copper. Thus, Coptrol should not be used in water sources where sheep are grazing on Ragwort.

Water treated with Coptrol at copper levels of 0.2 ppm to 1.0 ppm presents no hazard when used for watering or irrigating green pastures or crops. Copper, as a micro‑nutrient, is frequently included in all‑purpose fertilisers. Copper is also used liberally in horticultural pesticide formulations, such as Bordeaux mixture.

Irrigation systems supplied from dams or ponds are often affected by filamentous algae, especially during warmer months. Filamentous algae are easily identified by its stringy structure and are associated with blocking foot valves in dams and clogging drip irrigation systems. Coptrol will not affect your irrigation system, it will help stop the growth and eliminate the chronic problems associated with algal growth.

Coptrol will not adversely affect plants and may be used immediately to water fairways, putting greens and ornamental plants.

Coptrol is approved by the APVMA (Australian Pesticides and Veterinary Medicines Authority: Reg No. 31030) for application in potable water (water suitable for drinking).

When used as directed by the product label, water treated with Coptrol can be consumed by dogs, cats and other pets.

Algae, or brown/green slime, are a perpetual problem in rice crops in Australia and in other parts of the world. In some years there is so much algae slime in the water that great slabs lie all over the surface smothering the emerging crop.

Coptrol is a chelated copper algaecide that offers a new approach in the prevention and control of free-floating and filamentous algae in rice.

Far from being irritant and invasive, it is extremely adaptable in application.

It can:

  • Piggyback on herbicide and insecticides flown on to aerially sown or drill sown crops.
  • Be mixed with water and dripped in to water flowing into bays.
  • Be poured from banks directly into flooded bays.

Coptrol is not compatible with chlorpyrifos.

Application Questions

Before applying the product please read the Safety Data Sheet (SDS) and the product label.

Follow our 5-step Coptrol algaecide application method: Identify, measure, dose, dilute, apply.

Coptrol may be applied from aircraft or boats. It can be also be sprayed from the banks of larger water storages. It may be dripped directly into flowing water in high volume treatments such as flood irrigation water.

Coptrol is a highly soluble liquid. For farm and dam application, dilute 1:10 to 1:20 with water. Spray the solution using large droplets evenly over the surface. Do not spray on a windy day.

The activity of Coptrol depends on the level of algae present at the time of treatment and the amount of Coptrol used. Coptrol is consumed by the algal population, as it is absorbed into the algal cell wall.

Yes. Coptrol can be used get rid of algae at any time of the year, providing water temperature does not fall below 16°C (60.8°F).

The shelf-life is 3 years.


Coptrol should not be used in or discharged into rivers, streams, creeks, billabongs, lakes or wetlands.

  • This product is not intended to control aquatic weeds. 
  • Do not use Coptrol if water temperature is below 16°C.
  • Some fish and crustacean species may be sensitive to Coptrol in low water hardness. Please check the product label for more instructions.
  • Do not use if Calcium Carbonate levels are 50ppm or lower.