Aquarium and pond fish kept in an artificial environment are particularly prone to parasitic infestations even in the most careful situations.

For a mixed population tropical tank this can be devastating and for the Koi carp keeper a nightmare. Good housekeeping is always the starting point, but often the slightest imbalance in any number of factors can result in the almost spontaneous appearance of parasites ranging from the common Ich in the aquarium, to the more serious Costia and Trichodina in Koi carp, not to mention fungus and louse infestations.

Microscopes are ideal for finding what parasite you need to treat for. Instead of just bunging in all types of medication and crossing your fingers.