C/N ratio refers to the ratio of available organic carbon and available nitrogen in aquaculture pond water. Both carbon and nitrogen are nutrients of microorganisms and algae in aquaculture water. Nitrogen source is mainly bait residue and feces, while organic carbon source is mainly photosynthesis of algae.
Importance of carbon sources in water bodies
Carbon source is a very important nutrient element for algae. In the process of cultivation, the reason why algae cannot grow due to the lack of carbon is believed to be understood by many farming friends. Many farming friends apply a lot of fertilizer in the early stage of fertilizer and water, resulting in high ammonia nitrogen in the pond and relatively thin water. Sunny ponds in the middle and late stage of culture are prone to "algae dumping", with more foam, algae aging, and higher ammonia nitrogen or nitrite, which are mostly related to insufficient carbon sources in the water.
In general, the pond does not need to supplement the nitrogen source, pay attention to supplement the carbon source. We should pay attention to these points when supplementing carbon sources:
1. Due to different farming modes, such as factory, high-altitude ponds, earthen ponds and bioflocs, the requirements for carbon source ratio of ponds are different.
2. The supplementary carbon source is different for different periods of culture (main reason)
3. The higher the protein in the feed, the more carbon sources should be added. Is the later stage of breeding feed input, the increase of pond nitrogen elements).
Benefits of adding carbon sources
1. Adding carbon sources to the pond will accelerate the decomposition of nitrogen elements, such as ammonia nitrogen, nitrite, nitrate, etc., and significantly reduce the increase of toxic and harmful substances in the pond; The addition of carbon sources can significantly promote nitrification and increase the number of nitrifying bacteria.
2. Increasing the C/N ratio can effectively reduce the content of Vibrio in the pond, and the growth of beneficial bacteria can promote the reproduction of beneficial bacteria and inhibit the growth of harmful bacteria in the pond.
3. Promote the growth of beneficial algae and avoid the outbreak of bad algae such as cyanobacteria: cyanobacteria are very nitrogen loving. When the ratio of carbon to nitrogen is unbalanced, the content of nitrogen increases, and the carbon element is relatively reduced, that is, the ratio of carbon to nitrogen is reduced, and cyanobacteria can make full use of nitrogen, which will easily lead to the outbreak of cyanobacteria.