WATER QUALITY MONITORING INTO A RECIRCULATING AQUACULTURE SYSTEM FOR INTENSIVE REARING OF CARP (CYPRINUS CARPIO) JUVENILES FED WITH PROBIOTICS SUPPLEMENT

Elena Bocioc, V. Cristea, N. Patriche, Iulia Grecu, Săndiţa (Placintă) Ion, M.T. Coadă, T.I. Ionescu

Abstract
Dynamics of water quality parameters in an intensive recirculating system of juvenile carp (Cyprinus carpio) is dependent on many factors, the most important being the stocking density, feeding intensity and biochemical composition of the feed. The objective of this work is the monitoring of chemical parameters of physical environment in culture conditions in a recirculating system using a probiotic feed and monitor the evolution of these parameters during the experiment. We have evaluated the main water quality parameters, namely temperature, the pH, oxygen, ammonia, nitrites, nitrates and chlorine. Temperature, water and oxygen and the reaction caused by sensors in the automatic control system quality water, and for other parameters was used to determine colorimetric method with kits with Merck type Spectroquant Nova 400. With the use of a probiotic feed containing 30% protein and varying concentrations of probiotic BioPlus 2B®, consisting of Bacillus licheniformis (DSM 5749) and Bacillus subtilis (DSM 5750) in a ratio of 1:1, recycled water quality was maintained in the allowable spread of culture supported by the species. During the experiment, their values were within the following spacing: ammoniacal nitrogen (N-NH₄⁺) from 0,17 to 0,86 mg / l; Nitrites (N-NO₂) 0,24 to 0,54 mg / l; Nitrate (N-NO₃) 16,7 - 20,4 mg / l and chlorine (Cl^-) 23,4 to 32,3 mg / l.

Key words: recirculating system, probiotic feed, water quality, carp