Vliv obsádky na dynamiku hydrochemických parametrů v systému intenzivního chovu lososovitých ryb

Aim of the thesis was to evaluate the influence of fish stock on the hydrochemical parameters of the water in Recirculating systems. A part of the work was elaboration of the literature review on the topic. In the experimental part was performed several trials under laboratory and practical conditions. The first trial aimed on comparison of hydrochemical parameters between recilculating system with biological filtration and recirculating system without biological filtration. There was studied a content of nitrogen compounds. The content of ammonia nitrogen was higher in the system without filtration (0.2 -- 1.0 mg.l-1) than in the system with biological filtration (0.1 -- 0.4 mg.l-1). In the system with the biological filtration was higher a content of the nitrite nitrogen ranged from 0.14 to 0.16 mg.l-1. In the system without filtration ranged content of nitrite nitrogen from 0.01 to 0.1 mg.l-1. In the next trial was monitored a development of the hydro chemical parameters in recirculating systems after their launch. Two monitoring was made. In the first three weeks was observed increased content of ammonium nitrogen, after its reduction increased nitrite nitrogen. These compounds were sufficiently degraded roughly after a one month. The third trial was aimed on changes in recirculating systems during 24 hours. Monitored were contents of nitrogen compounds, oxygen and pH. The lowest content of ammonium nitrogen was registered at night. The biggest increase of ammonium nitrogen was found after feeding of the fish. Content of nitrite nitrogen increased during monitoring due to biological degradation of ammonium nitrogen in filter. The biggest decrease of oxygen was registered after fish feeding. Oxygen decreased op to 10 percent. The pH continuously decreased during monitoring due to CO2 production of fish and biological processes in filter