What are the correct ways to use fish medication?
The following details should be grasped when using fish medication correctly:
1. Identify the disease. Different drugs prevent and treat different fish diseases. When treating fish diseases, a correct diagnosis of the disease should be made and the right medicine prescribed for the illness so that the drug can take effect and achieve a therapeutic result. Generally speaking, different pathogens have different symptoms, but there are also some fish diseases whose symptoms are similar or identical yet whose pathogens differ, so careful diagnosis and differentiation are required before selecting the most effective therapeutic drug.
2. Drug properties. Fish medication can be divided into two major categories, chemical drugs and Chinese herbal medicines. These drugs each have their own physicochemical characteristics, and if these characteristics are ignored, sometimes the treatment will still be ineffective even though the drug matches the illness and the method of use is correct. For example, bleaching powder readily deliquesces in air and loses its available chlorine; quicklime will turn into powdery calcium carbonate over a long time and become ineffective; the water temperature for dissolving copper sulfate must not exceed 60°C, while diflubenzuron must be soaked in water above 60°C.
3. Drug dosage. All drugs have a certain effective concentration; too little is ineffective, and too much causes poisoning. The pond area and water depth should be measured accurately, the pond water volume calculated (for oral medication, the body weight of the fish in the pond should be estimated fairly accurately), and then the dosage converted according to the medication concentration, so that the drug's effect can be both safe and effective. At the same time, the pond environment, water quality and so on also have a certain influence on the drug; for ponds with fertile water and heavy pollution, the dosage should be appropriately increased.
4. Medication method
The medication method should be determined according to the type of pathogen, the drug properties and the condition of the fish. Ectoparasites are suitable for splash treatment, while digestive tract parasites should be treated orally; bacterial diseases are generally treated by the splash method. Soluble drugs can be both splashed and taken orally, while insoluble drugs can only be taken orally. If the fish have lost the ability to feed, splash treatment should be used; if the fish still have feeding ability, oral administration is preferable. Drugs with antagonistic effects cannot be used at the same time, such as insecticides and quicklime. Overall, oral administration acts more completely than splash treatment; if the pathogen mainly attacks the fish's body surface, then splash treatment should be used, and if the pathogen mainly attacks the inside of the fish's body, then oral administration is preferable; for preventing fish diseases, a combination of splash treatment and oral administration is better. At the same time, fish illness is often the result of several pathogens acting simultaneously, so treatment should target parasites first and bacteria second, that is, treat parasitic diseases first and then bacterial diseases, to avoid repeated infection. In a single pond, repeated use of medication should also be avoided as much as possible so that pathogens do not develop drug resistance.
5. Medication time. The medication time should be determined according to the type of drug and the symptoms. For treating parasitic diseases, around 10 a.m., when the pathogens have weak vitality and are easy to kill; for bacterial diseases, it is preferable to carry out treatment around 2 p.m., when the water temperature is high, dissolved oxygen is abundant, and the drug's action is strong. Drugs that are easily oxidized should be used on cloudy days or in the evening, such as potassium permanganate. Medicated bait should be given during the first two feedings each day.