Virkon Aquatic Fish Biosecurity

Virkon S and Virkon aquatic

Virkon Aquatic is currently only available as a special import order, while Virkon S is manufactured in South Africa. Due to import costs, Virkon Aquatic is a lot more expensive than Virkon S.

What is the difference betweenVirkon Aquaticand Virkon-S?

Virkon Aquatic was first made available in the USA in May of 2007 and it is specifically designed for use in fish culture.  Virkon-S is designed for use in the production of poultry, swine, and other types of agriculture.  Virkon Aquatic is made without the indicator dye or perfume that is found in Virkon-S.  These have been removed to make the product safe for use around fish and other aquatic life.  Virkon Aquatic has a formulation based on the same active ingredients as Virkon-S but it’s inert ingredients are chosen for safe use in aquatic applications.  There are also important EPA labeling differences between Virkon Aquatic and Virkon-S.  The EPA approved label for Virkon Aquatic contains expanded aquaculture claims and applications and is approved for use in aquaculture.  Virkon-S is no longer recommended for use in aquaculture and its label will no longer carry EPA approval for aquaculture claims.

In summary, Virkon-S should not be used where it will come in contact with live animals like fish, but can be used for equipment and surfaces.

However, this usage link, data source:, treats both products as the same and advises:

VirkonS® and Virkon® Aquatic

500 gram is sufficient for 500.000 liter pond maintenance. VirkonS® and Virkon® Aquatic is a pond disinfectant. It kills It kills pathogens, reduces the bacteria germs (CFU Colony forming units), fights viruses, bacteria and fungi. Koi are usually held in closed circuit systems to ensure good health, many of the skills and knowledge refer to the ability of the hobbyist, to create optimal filtering systems and thus an optimum water quality. In recent years, 2 very serious viral diseases have appeared, wich can lead to very serious loss in koi. These are called “Koi Herpes Virus (KHV) and” Spring Viraemia, both diseases among cyprinids. As with all viral diseases, there is no specific treatment available. Biosecurity measurements in combination with supportive measures, as applied in livestock branches, make sure that it does not spread. That is the maximum what can be achieved in this matter. Nowadays many owners of Koi and traders are much more aware of the danger. They feel the need for a form of Biosecurity as it is the only way to protect their often-valuable property and safeguard these problems. Biosecurity for Koi owners is based on the same principles as consumptional fishfarming. However, now with the added complication of the closed circuit filter, which can be a haven for all kinds of infectious diseases. These biofilters, however, will be damaged or die when disinfectants are used. To prevent loss of Koi and reduce any virus diseases, we have successfully developed adapted Biosecurity programs. These programs help improve the health and welfare of Koi and are even used in commercial farms.

VirkonS® and Virkon® Aquatic is what?

Several viruses, including ‘Herpes’ form serious threats to Koi owners. Many fish are carriers without showing any signs of this. When these are put in contact with susceptible fish, they can-especially if there is stress, release the virus into the water, leading to infections and high mortality. Independent evidence shows that Virkon is effective against most significant fish disease / pathogens. Recent research has shown that, if Virkon is continuously added to the water of fish farms, with a dosage of 2 grams per 1000 liters of water, Virkon dissolves in the water and shows only very low toxicity. This dose does not disinfect the water completely, such as concentrated disinfectants would, but purifies it and reduces availability of virus infections. It is better to speak of ‘a form of waterconditioning’ as of decontamination or disinfection. A very important feature for use in koi ponds of Virkon is that the level of pathogenic bacteria and some protozoan parasites in the water is greatly reduced. (The bacterial pressure). Studies in the USA with Koi have shown that continuous use of Virkon on carp in water at a dose of 8 grams per 1000 liters of water has no harmful effect on the health of the fish. Virkon is proven highly effective against herpes and Rhabdo viruses. Unlike fishfarms Koi are held in closed circuit systems with biological filters in which water circulates. This makes the continuous dosing with fresh water very difficult. Because different viruses, including “Herpes” are such a big potential problem, “DuPont’s Animal Health Solutions searched for a solutution in cooperation with Biosecurity. A system is developed, which under normal circumstances will give a good water condition at the Koi owner. All this without negative effect on the operation of biological filters or the concentration of Virkon reaching toxic levels.
Virkon is essentially a powerful complex formulated virus killing disinfectant for disinfection of aquatic equipment. It is now used effectively in many Koi ponds in Europe and USA to purify the water of different viruses, including ‘herpes’ at a dose of 8 grams per 1,000 liters of water. Because all Koi filters, pond systems
and water chemistry are different everywhere, this document may only be issued on a consultative basis.
The Purification of the water in koi ponds with Virkon Most koi ponds are equipped with a pump, a microbiological filter and a UV lamp. Before dosing UV and / or ozone components ares to be switched off. After dosing, once Virkon is circulated in the pond water, UV and / or ozone may be turned back on. Make sure that the circulation pump(s) are working, while spreading Virkon.

Dosage / Usage:

Mix VirkonS® or Virkon® Aquatic in a bucket of water and spread it evenly over the pond / quarantine. Switch off any UV and / or ozone equipment. After dosing, once Virkon circulated in the pond water UV and / or Ozone may be turned back on. Preventive use: For a constant lowered bacterial pressure and continuously conditioned pondwater dose 1 gram on a 1000 liters of pond water weekly. It is very important to refresh 5-10% of the water volume prior to the weekly re-dosage. Preventive use Spring / Autumn: To reduce the bacterial pressure in a period of three weeks, dose 2 grams to 1000 liters of pond water weekly. It is very important to refresh 5-10% of the water volume prior to the weekly re-dosage.
Preventive use in placing new Koi in quarantine system: Stick to a quarantine period of several weeks. Dose 2 grams to 1000 liters of water at a frequency of 2 times per week. It is very important to refresh 5-10% of the water volume prior to the weekly re-dosage. Preventive use in pond after quarantine period: to reduce the bacterial pressure over a period of three weeks, dose 2 grams to 1000 liters of pond water weekly. It is very important to refresh 5-10% of the water volume prior to the weekly re-dosage. After this period, place the fish in the pond. For persistent viruses and bacteria: In 7 days consecutive, dose 5 gram to 1000 liters of pond water. At this treatment level, it is essential that you change 10% of the water volume weekly.


Dose as follows: add the desired amount of Virkon to 10 liters of pond water. Stir until the powder has dissolved and gradually add the solution to the pond water. A dispensing system can easily be made from a plastic bucket where at the bottom a hole is punctured. The solution is slowly released to the water. Make sure that the pumps are operating, so that distribution is optimal. Virkon contains a small amount of lipophilic surfactant, especially active against viruses of external enclosures. This substance can accumulate on the water surface and produce foam over time, especially if the required water changes are not enforced.
Warning: Irritating to skin, Risk of serious damage to eyes, Keep out of reach of children, Avoid contact with skin and eyes In case of contact with eyes, rinse immediately with plenty of water and seek medical advice, Wear suitable protective clothing, gloves and eye/face This material and its container must be disposed of as hazardous waste.

Aquaculture biosecurity

For more on Virkon’s use in aquaculture biosecurity for fish and shrimps (prawns, invertebrates), see:

Shrimp production

Fish production