Hydrochemical monitoring is the basis for planning production processes in full-system fish farming

The article describes the results of hydrochemical analysis of the water of breeding pond No. 1A of PrJSC “Vilshanka” in the spring-autumn period of 2023 for the cultivation of carp (Cyprinus carpio) and sterlet (Acipenser ruthenus) in polyculture. The results of the study of the hydrogen index (pH) of water during the entire period of research showed that it was in the range of 7.6 to 8.4 and did not exceed the norms. The concentration of ammonium nitrogen in water due to anthropogenic load increased in all experiment periods; however, the studied indicator, which ranged from 0.39 ± 0.03 to 0.68 ± 0.05 mg N/dm3, did not exceed the standard's requirements. The results of studies of nitrite nitrogen content in water ranged from 0.05 ± 0.002 to 0.12 ± 0.009 mg N/dm3. Still, it, like the content of ammonium nitrogen, did not exceed the standard's requirements, indicating the absence of nitrification processes of ammonium nitrogen in the water. The analysis of the results of research on the concentration of nitrate nitrogen in water was within 1.37 ± 0.07 – 1.75 ± 0.11 mg N/dm3 of fluctuations in the content of nitrogen compounds in water, which is associated with anthropogenic load, which includes getting into water runoff from the fields, as well as biological decomposition of organic substances that enter the water at different times of the year. The content of phosphates ranged from 0.41 to 0.53 mg/dm3 and did not exceed the standard's requirements. Dichromate oxidizability ranged from 14.4 to 28.3 O2/dm3, but, if compared with average values, it was 1.17 times higher in spring, 1.89 times higher in summer, and 1.89 times higher in autumn 1.83 times, indicating possible emissions of chemical compounds into water, such as heavy metals and other toxic substances, which will lead to disruption of natural ecosystems. Analyzing the data of BSK5, which ranged from 4 to 6.9 mg/dm3 in the water of growth pond No. 1A, was similar to changes to dichromate oxidation and changed depending on the season.