Most koi parasites are not visible to the naked eye. In order to correctly identify any koi parasites you will need a microscope with built in light and a magnification of 400 times.
These are simple to use and are an essential piece of kit for any koi keeper.
To accurately detect any koi parasite causing an infestation of your koi, you will need to take a skin scrape. This involves using a microscope slide to carefully remove a small quantity of mucus from one of your koi. The mucus is then sandwiched between the slide and a cover slip and inspected through the microscope. We would recommend that upon purchasing your microscope, you ask your koi dealer to demonstrate this technique to you. This will help avoid causing any possible damage to your koi.
If you suspect you have a koi parasite problem, skin scrapes need only be taken from two or three koi, if parasites are found, it is safe to assume all koi are infested by the parasite and therefore the entire pond will require treatment.
Before any parasite treatment is used in your koi pond, it is vital that you know the exact volume of water and temperature, and that adequate filtration and aeration is provided. Parasite treatments will lower the dissolved oxygen levels in the pond so we recommend adding additional aeration when using any chemicals in your koi pond. You must also switch off any ultra violet sterilisers / clarifiers and ozone equipment.