Is Virkon® Aquatic a medicine?
No.Virkon will not treat fish or shellfish, but it will disinfect hard surfaces, boots, clothing etc., provided they are clean. If used in a fine spray into the atmosphere, a technique known as “Virkon fogging”, it will greatly reduce or eliminate airborne pathogens and also percolate through rafters or other areas of buildings otherwise not possible to access.
In addition, if added to the water in which fish are swimming, at high dilution (ca 2ppm) and on a continuous basis, it will greatly reduce the level of bacteria, viruses and certain parasites which can survive in the water and thus prevent or reduce levels of potential infection. It does this by removing them from the water and not from the fish. It is not likely to have any significant direct effect, good or bad, on the fish themselves at these concentrations.
Can Virkon® Aquatic, if used continuously, affect my biological filter or my domestic septic tank?
Research by The Water Research Centre showed that even at full disinfectant levels, use of Virkon® Aquatic does not affect the efficiency of septic tanks. However, where it is dripped continuously into Koi systems to maintain a standing level of 2ppm in the water column, it can affect biological water filters if there is no removal and replacement of a percentage of the water (make-up) once a week. Usually make up of 25% weekly is necessary where it is being used continuously to prevent or control presence of Koi Herpes Virus in the water column. Signs that the filter is becoming challenged include increased nitrate build up in the water and excessive foaming. A small amount of foaming is normal and necessary to destroy the lipid envelope of koi herpes virus (KHV), infectious salmon anaemia virus (ISA) and others.
What is the recommended concentration for Virkon® Aquatic in water?
We recommend 2 to 4 ppm (parts per million) for continuous dosing in a flow through system, and up to 8 ppm for initial dosing of a closed Koi pond recirculation system. Do not use any Virkon formulation other than Virkon® Aquatic.
How do I dose a fixed volume of water with Virkon Aquatic at 2ppm?
Remember that 2 ppm is 0.002 grams of product so for example a 10,000 litre tank of water will require 10,000 x 0.002 g = 20 grams of product. 1,000 gallons requires approximately one 5 gram tablet of Virkon Aquatic to produce 2ppm. We recommend an initial dose of 8ppm for a koi pond so this would equate to using 4 tablets, diluted and added slowly below the filter inflow to the pond, to create 8ppm in a 1,000 gallon pond. This will rapidly break down to natural products, but while active it will strongly sanitize the microbial flora and particularly viruses.
How often do I redose a fixed volume of water such as a Koi pond?
This should not be done more frequently than once a week unless there is a known virus threat, and it is recommended that at least 5-10% of the water is changed at the same time, as although Virkon Aquatic breaks down in the filter system, there is a trace of detergent in the product which helps it deal with viruses in biofilms. Over time this detergent can build up if there is no water turnover. It can be detected if foaming is seen around the edge of the tank, though it rarely occurs in normal usage.
What is the difference between Virkon® Aquatic and other Virkon disinfectants?
Virkon® Aquatic is the registered trade mark for the specially adapted patented formulation of the most widely tested and approved virucidal and bactericidal disinfection in the world. All Antec/DuPont Virkons use the Haber Willstater reaction to harness the separate antiviral activities of oxyzones, fruit acid salts and potassium monopersulphonate, to regenerate activity continuously and also incorporate a high level of detergent for ensuring cleaning of muddy boots etc in the pig or poultry context.
Virkon® Aquatic has been modified so that while maintaining and indeed enhancing its virucidal activities, particularly against fish pathogens, it has reduced detergent activity, which is very toxic to aquatic animals. The fragrance, which is highly tainting for fish is also removed.The indicator dye used is also one which is not banned for food usage in certain countries.
Because of concerns about possible toxicity and tainting in use in aquatic sector, DuPont the manufacturer does not support or take any responsibility for any usage of any Virkon other than Virkon® Aquatic in any aquatic usage context.