POVIDONE-IODINE (PVP-I) IN AQUACULTURE
A. Overview about Povidone Iodine(PVP-I)
There are many different types of Iodine with Iodine ingredients and solvents. However, the mention of Iodine in aquaculture is referring to Povidone-iodine (PVP-I). This is a chemical compound belonging to the halogen group with strong oxidizing properties. In terms of chemical structure, it is composed of a complex of soluble solvent, also known as the carrier Polyvinyl pyrrolidone (PVP) with Iodine(I2) and the content of Iodine in PVP-I contains from 9.0% to 12 %.
PVP-I in powder form has a dark red color, a characteristic odor, is completely soluble in water, and has higher stability than alcohol iodine and logon. Because of such a structure, when using PVP-I, iodine will be released slowly into the surrounding environment and minimize toxicity to shrimp, fish, and frogs compared to normal forms of Iodine.
B. Disinfection mechanism
When Povidone-iodine enters the water, free iodine is slowly released from the PVP-iodine mixture and has the main mechanisms of action:
Iodine freely penetrates the cell walls and membranes of: protozoa, fungi, bacteria, and viruses.
· Iodine can attach to the NH group of amino acids, thus breaking the structure of proteins; Oxidation of the SH group of sulfur-containing amino acids breaks the S-S bond, so protein cannot be synthesized.
Breaking the C=C bridge in fatty acids in cell membranes.
The gradual release of iodine from the PVP–iodine compound should have a good antiseptic effect, a long-lasting effect and help reduce the toxicity of Iodine to mammalian cells.
C. Application of Iodine in aquaculture
Advantages of PVP-I in aquaculture:
Can be used directly in ponds without fear of affecting the health of shrimp, fish, frogs, snakeheads..
Does not irritate the skin, does not cause allergies to the user.
PVP-I slowly releases iodine into the environment, so the sterilization and disinfection effect is prolonged.
· Does not form compounds that accumulate on the pond bottom during use.
Does not affect algae growth in ponds when used.
· Does not corrode metals and make bottles of plastic objects.
Notes when using Iodine
- For all kinds of Iodine, especially Povidone Iodine has a good effect when pH: 3- 6.
- Periodic use of pond treatment: 1L PVP-I/2,000-4,000m3 of water
- When fish, shrimp, frog… get sick: 1L PVP-I/1,000-2,000m3 of water (Try or bathe)
- Use in cool weather because the drug loses its effect quickly at temperatures above 35oC and at the same time sunlight also makes the drug decompose quickly.
- You also need to pay attention to the ability to kill all beneficial microorganisms in the water and pond bottom, thereby inhibiting the decomposition of organic matter in the pond.
- Iodine types have the ability to kill plankton, a natural food source for fish and shrimp, so it is necessary to pay attention to the dosage when using.
