Introduction of commonly used drugs for fish 1

At present, there are many kinds of commonly used drugs on the market. As the production of fish medicine is not standardized, some of the products of various manufacturers are not marked with active ingredients, and the trade names of some similar proprietary medicines are not unified with the corresponding chemical names. This is not conducive for us to understand the effective components of drugs, and it also causes some difficulties for the scientific and rational use of drugs. In order to popularize the technology of prevention and control of fish diseases, we will introduce the knowledge of commonly used drugs in fish culture one after another. In order to improve our understanding and understanding of commonly used drugs, we can use drugs scientifically and rationally in production.

One. Disinfectant and fungicide

There are many kinds of disinfection and antiseptic drugs commonly used in pond fish culture for the prevention and treatment of bacterial fish diseases, most of which are compounds containing chlorine, among which the most commonly used are bleach, bleach, dichloride, trichloride and chlorine dioxide.

(1) bleaching powder

Bleaching powder is a mixture of calcium hypochlorite, calcium hydroxide and calcium chloride. The finished product is gray-white powder with chlorine odor. Its aqueous solution is turbid, suspended with a large amount of sediment, and the stability of bleaching powder is very poor. Exposed in the air, it can absorb water, decompose slowly, and react with carbon dioxide in the air. Failure due to the formation of calcium chloride with no bactericidal effect. The storage time is usually three to six months. Storage conditions should be sealed in a cool and dry place. The shelf life of high air humidity in summer is relatively shortened. It is generally appropriate to buy those with a short factory delivery time. The content of available chlorine should not be less than 25%. The available chlorine of bleaching powder can be determined by the following simple method.

1. Material preparation

A bottle of ⑴ blue and black ink. Generally, you can use blue and black ink such as Beijing card or hero card. As long as there is no water and no precipitation can be used.

1 ⑵ 1 ml pipette. A syringe with a scale of 0.1 ml can also be used instead of a syringe of 1 ml to 2 ml.

A small white porcelain bowl of ⑶

A ⑷ glass rod, or a non-absorbent plastic rod

⑸ 100ml measuring cylinder, can also be replaced by a graduated medicine bottle or infusion salt bottle

⑹ ordinary small balance can also be replaced by a small hand scale with high precision.

2. Determination method

When taking bleach samples that need to be determined for available chlorine, ⑴ should adopt the method of random sampling. Generally, roughly the same amount (about tens of grams) of bleach powder (about tens of grams) can be randomly taken from different parts (upper, middle and lower layers) of three to five containers, and then mixed evenly as samples to be tested.

⑵ weighs 5 grams of bleach sample, put it in a measuring cylinder, add a small amount of boiled cooled drinking water (no dissolved carbon dioxide in the water is required), stir and grind the bleach and water with a glass stick, and then dilute it to 100ml. Set still after full stirring

After the solution is clarified, ⑶ uses a pipette or syringe to absorb a certain amount of the upper clear liquid and drop it into the white porcelain bowl with a total of 38 drops (neither more nor less).

⑷ will wash the used pipette or syringe, shake it dry; absorb a small amount of blue ink to clean the pipe wall with blue ink, then discard it, absorb the blue ink again, titrate the bleach solution in the porcelain bowl, stir it with a clean glass stick while dripping, change the color of the bleach solution from brown to yellow, and finally show a stable blue-green color, that is the titration end point.

The number of drops of blue ink used in ⑸ is the percentage of available chlorine in bleach (for example, with 24 drops of blue ink, the available chlorine in bleach is 24%).

[action] the bleach was added to the water to produce hypochlorite and alkaline calcium chloride, and the hypochlorite was instantly decomposed into active chlorine and atomic oxygen, showing bactericidal effect. The bactericidal effect of hypochlorite ion in active chlorine is weak, and its action principle is chlorination and oxidation, as well as inhibiting the activity of some enzymes containing sulfhydryl groups, which hinders the growth and reproduction of bacteria. Its bactericidal effect is strong, but not long-lasting. Its germicidal use is enhanced in acidic environment, while its germicidal effect is weakened in alkaline environment.

[use] bleaching powder is one of the commonly used drugs in the prevention and treatment of fish disease. it is mainly used to control bacterial fish disease and to kill bacteria in fish in vitro and in water.

[usage and dosage]

1, clear the pond disinfection: dry method, the dosage is 1020kg per mu; clear the pond with water, 2535kg per mu of water surface (water depth 1 meter).

2. Sprinkle the whole pond: make the concentration of pond water 1ppm (1 mg per liter of water), which can be used to prevent and cure bacterial fish diseases such as Gill rot, red skin disease, white head and white mouth disease.

3, fish seed disinfection: medicine bath, 10~20ppm aqueous solution soaking for 10 minutes for 30 minutes, can kill bacteria on the body surface and gills of aquatic animals.

4. Bait disinfection: the aquatic plants were soaked in 6~10ppm bleach solution for 20 minutes for 30 minutes, and Artemia eggs were soaked in 300ppm solution for disinfection, then washed until there was no chlorine smell.

5. Tool disinfection: 5% bleach powder aqueous solution is washed and disinfected.

6. food farm disinfection: regularly sprinkle bleach in the food farm, the dosage depends on the size, water depth and water temperature of the food field, generally 250g to 500g. Sprinkle the medicine before feeding the fish. Hanging baskets can also be used in the food market (waste mineral water bottles can be used to drill holes instead of bamboo baskets) to prevent and cure fish diseases.