When copper sulfate is used in aquatic products, ferrous sulfate is often added. Half a kilogram of copper sulfate is added with 22 ferrous sulfate. Usually, it is poured out at the dose of 0.7ppm. Because it is widely used, many farmers mistakenly think that ferrous sulfate can kill insects. In fact, ferrous sulfate does not kill insects at all. On the contrary, excessive dosage will also affect the content of phosphorus in water. In this case, some people may be confused, so why add this drug to insecticides such as copper sulfate and trichlorfon? Let's write it today.
Ferrous sulfate is divided into two kinds. One is white powder, which has no taste and will be weathered in dry air. Its scientific name is anhydrous ferrous sulfate; The other is our commonly used light green crystalline ferrous sulfate, which contains crystalline water, commonly known as "green alum", which has a pungent taste. The aqueous solution is light green, a little like the color of blue and black ink we use to write with a pen.
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It is understood that the ink really contains ferrous sulfate, as well as some agricultural pesticides. When I was a child, my hometown was full of oranges everywhere. At that time, it was easy to suffer from trunk rot. we dissolved ferrous sulfate into water and coated it with quicklime and copper sulfate on the tree stem, which can not only kill insects, but also remove the moss on the tree stem; In addition, like the flowers and plants we grow, especially some plants that like acidic soil, when the soil is alkalized, it is easy to hinder the absorption of ferrous ions, and the leaves are easy to turn yellow. At this time, we only need to supplement the fertilizer containing ferrous sulfate, so ferrous sulfate is also used for fertilizer.
Talking about the use of ferrous sulfate in pesticides and fertilizers, what is the function of ferrous sulfate in aquatic products? That is to use its flocculation and debonding function. This function is also useful in environmental protection: the sewage treatment plant will use ferrous sulfate to remove phosphate from the water body, purify the water quality and prevent eutrophication. In aquatic products, it is more used to eliminate the fixation on the surface of fish skin, make mucosal cells fall off, increase the contact between drugs and lesions and parasites, and increase the permeability of drugs. For example, the rotten gills and gill filaments caused by some parasites are inflamed and swollen, and many mucus are attached. If these mucus are not removed, when external insecticides are used, these mucus will become the natural protective agent of parasites and hinder the contact between drugs and insects. For example, ciliate parasites such as gill cryptoflagellate, mouth filariasis, wheel worm, oblique tube worm, capillary worm and tongue cup worm are easy to affect the efficacy due to mucus. Now many fishery pharmaceutical factories are studying how to improve the solubilization and permeability.
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When ferrous sulfate is used in aquatic products, it should be noted that snakehead is very sensitive to this drug, and it can usually be used at a dose of 0.2ppm on other fish. In addition, when ferrous sulfate is used in water and mixed with quinolones in feed, it will affect the absorption of drug concentration. As for the degree of impact, no exact data have been found, and researchers are expected to do research in this field.