Bath treatments are also used in cages, where a tarpaulin is pulled around the cage to enclose it and the chemical added. At the end of the treatment period the tarpaulin is removed. Flush A slug of chemical is added to a raceway or trough and allowed to pass down through the raceway with clean freshwater following behind. This is used in applications where it is impossible to turn the water off for a bath treatment due to limitations such as a lack of oxygen. This is used to good effect with eggs but with fish, their ability to swim through the chemical into the clean water, above gives variable results as the contact time cannot be guaranteed.
Drips are sometimes with the antifungal chemicals used for eggs.
The easiest method for this is to net the fish from the tank and immerse the whole net and fish into the chemical. Used primarily for immersion vaccination, but also for the treatment of some parasites. Swab A piece of cloth or cotton wool is dipped into a high concentration of chemical and wiped of the fish. Impractical for large numbers of fish but sometimes used for the treatment of localised infections on valuable broodfish. Injection Injection of chemicals into the body of the fish is a process used by many farms for the administration of vaccines.