How to use Coptrol to control Algae in

Aquaculture

Algae consume important nutrients and oxygen|dissolved oxygen|phytoplankton

Free floating and filamentous and blue green algae, (cyanobacteria) are a constant problem in aquatic environments.

In the nutrient rich, oxygenated waters found in aquaculture algal blooms compete with fish and crustacea for:

dissolved oxygen
nutrients
Cyanobacteria dominate phytoplankton competing for available nitrogen
Cyanobacteria are able to regulate cell buoyancy and regulate their position in the water column to gain a distinct advantage over other organisms capable of synthesizing their own food from inorganic substances using solar or chemical energy.

For further information see our algae.info website.

Coptrol more effective and efficient|copper precipitation|hard water

The use of Coptrol in aquatic environments is a more efficient and

effective means of controlling algae than environmentally damaging

copper sulphate (bluestone) because:

Coptrol is environmentally friendly. It offers a new approach to the prevention and control of algae in aquaculture.

Coptrol eliminates the problem of copper precipitation in "hard" water.

Coptrol permits lower concentrations of copper to be used in algae control. Because Coptrol does not precipitate in hard water the application rates are less critical.

Coptrol achieves longer copper persistence in water at levels that are toxic to algae.

Coptrol is non-corrosive, non-irritant and easy to use.

Coptrol works in all kinds of water, salt or fresh, hard or soft, turbid or clear.

“Copper demand” explained

Copper has been used in balancing pond and water environments since

the inception of the aquaculture industry. However, the concentrations of

copper are critical and the "copper demand" of water varies widely. It is

essential that this demand be known, as copper will combine with carbonate

ions in water (which give the water its "hardness") to form insoluble copper carbonate. Thus, the copper goes out of the system and more must be

applied to achieve the correct balance. This is often a trial and error

process, which is costly in terms of time and money.

Copper in its ionic forms, e.g. copper sulphate, is potentially hazardous

to fish and presents some risk even when great care is taken in treating algae‑infested waters that contain fish. However, Coptrol (a chelated Coptrol use in fish ponds aqua

copper compound) is highly specific to algae and has been shown to present a minimum hazard to fish when used in accordance with the label.

Important Safety Principles |water hardness|water temperature|oxygen depletion|

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 crustacea. Water hardness may

be tested by using a commercial hardness test kit, or having a

small sample (about 250 mL) tested in any NATA registered laboratory.

Water temperature is also important. Below 16°C (61°F) spatiation

may occur where copper can separate from the chelating agent, potentially

being harmful to fish and crustacea.

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 or temperature below 16°C (61°F) Coptrol should not be used in the presence of valuable fish and crustacea.

Application to fish impoundments: Decomposing algae that has been

treated with Coptrol may lead to oxygen depletion of the water. Lack of

oxygen may cause fish to suffocate.

Therefore, in bodies of water containing fish, it is best to kill algae slowly. It is recommended to treat only one third of the area, then wait 10 days to allow the oxygen level to build up again. Then, resume the treatment beginning from the shore and moving outwards in bands to avoid trapping fish in treated areas.

Effects of copper on fish

A large number of studies have been conducted

on the toxicity of copper to fish, whether the copper is naturally occurring

or introduced.

Note ‑ the label cautions against the treatment of waters containing

trout and other species where water hardness is lower than 50 ppm.

Moore (1984) describes naturally occurring copper in the ionic form as potentially more toxic to fish than any other heavy metal except mercury. However, he notes that copper is much less toxic to fish in waters with a high complexing capacity, such as salt water. He also quotes data to confirm that copper is significantly less toxic to trout in hard waters.

Moore (1984), Stiff (1971) and Pagenkopf (1974) are in general agreement that ionic copper (Cu) and ionised hydroxides (such as CuOH) are the forms of copper most toxic to fish. Coptrol contains copper only in the chelated form, in

contrast to copper sulphate which presents copper only in the ionic

form.

Stiff (1971) noted that "natural" complexing of copper ions with glycine

and humic substances caused some reduction in copper toxicity.
Sprague in 1968 suggested that the chelating agent NTA (nitrilo-triacetic

acid) could be used as an anti‑pollutant to protect fish from copper

poisoning.

Boyd (1979) reported that chelated copper algaecides are often

recommended for application to soft water ponds to prevent copper

poisoning in fish. He further noted that "The toxicity of the chelated

(copper) compound to fish is less than that of an equal concentration

of copper in copper sulphate, so that species with a high susceptibility

to copper are not harmed in waters of low alkalinity". Moore (1984)

reported, "In copper polluted fresh waters, a maximum concentration

in muscle tissue seldom exceeds 1 mg/kg wet weight. Because muscle

residues are generally low; copper does not pose a threat to most

fisheries, even those in polluted waters.

See the full Coptrol Bibliography

Coptrol has been proven to be highly specific to algae and presents minimal risk to fish providing label instructions are followed exactly. Copper in any soluble form is potentially toxic to fish and crustacea. Extreme care should always be exercised in ensuring directions are accurately followed when treating algae infested waters containing fish.

When Coptrol is used, protection from copper toxicity is provided where

water hardness is more than 50 ppm. (50 mg/litre calcium carbonate).

If water

hardness is below 50ppm, Coptrol use is not recommended.

Shrimp/prawn farms |eel|fish|

Coptrol will eliminate a broad range of algae and control the growth of resistant species.

Coptrol will aid in the cure and control of diseases commonly found in shrimp. These include bacterial and gill diseases, tail ulcers and protozoan infections.

Treat shoreline first to avoid trapping aquatic livestock in shallows.

It is best to treat only 1/3 of the area at a time to avoid oxygen

depletion of the water caused by decaying vegetation.

Shrimp, Eel & Fish Dosing Table

Eel Ponds	Dose of Coptrol	Comments
To improve water quality and reduce "off flavour" and lower bacterial/parasitic load.	Use 1.7-2.0 p.p.m. 1.7-2.0 cc (mL) for 1 tonne of water	Dilute the required amount with 10 times the required volume of water. Pour or spray the resultant mixture evenly over the pond. After 2-3 days when algae dies, remove by hand. Repeat every 1-2 weeks.
Fish Ponds
Refer to eel ponds		Do not treat trout with coptrol unless water hardness is more than 50 p.p.m.

Warning
Do not use Coptrol in the rare cases where total water hardness (measured in grams of calcium carbonate (CaCO₃) is less than 50 p.p.m. Do not treat water if water temp is below 16⁰C (61°F).

Purpose	Dose of Coptrol	Comments
	For young shrimp	For young shrimp
To maintain water colour	Use 0.4-0.5 p.p.m equivalent to 0.4-0.5cc(mL) in 1 tonne (1000 litres) of water	If water colour is normal, continue dose after 5-7 days using low dose,frequent application method.
	For adult shrimp	For adult shrimp
To inhibit algal growth	Use 0.85-1.7 p.p.m concentration 0.85-1.7cc(mL) added to 1 tonne (1000 litres) of water.	One application every 1-2 weeks
	For young shrimp	For young shrimp
To induce moulting	Use 0.4-0.5 p.p.m equivalent to 0.4-0.5cc(mL) in 1 tonne (1000 litres) of water.	Continue after 5.7 days.
	For adult shrimp	For adult shrimp
To induce moulting	Use 0.85-1.7 p.p.m concentration 0.85-1.7cc(mL) added to 1 tonne (1000 litres) of water.	One application every 1-2 weeks.
To maintain water quality reduce off flavour Lower bacterial and parasitic loads.	Add 1.8cc(mL) per 1 tonne(1000 litres) of water.	Apply every 30 days as required.
Disease Prevention
Bacterial/Algal disease Including Black Gill and Red Gill disease. Tail Ulcers. Protozoa Infections. Mould Infections	Use.85-1.00 p.p.m. every 1-2 weeks as a preventative measure. .85-1.00 cc (mL) in 1 tonne (1000 litre) of water.
Disease Treatment
Bacterial/Algal disease Including Black Gill and Red Gill disease. Tail Ulcers. Protozoa Infections. Mould Infections	Use 1.7-2.00 p.p.m. 1.7-2.00 cc (mL) for 1 tonne (1000 litres) of water. After 2-3 days use 1-2 p.p.m. concentration again.	When disease is under control revert to prevention concentration of 0.85 p.p.m.
To eliminate heavy filamentous algal infestations such as cladophora, chlorella etc.	Use at a rate of 1.7-2.5 p.p.m. 1.7-2.5 cc (mL) for 1 tonne (1000 litres) of water	Treat 2 or 3 times. When algae starts to die and turns yellow remove by hand.

Coptrol Bibliography

Coptrol Frequently Asked Questions

Coptrol sales page

Coptrol Application rates

Material Safety Data Sheet