Use of natural bentonite clays in pond fish farming to create optimal concentrations of ammonium ionsTimur Tlupov, Karina Bambetova, Kamaludin Magomedov, Ruslan Kumykov and Nikolay KhalkoE3S Web Conf., 262 (2021) 02021DOI: https://doi.org/10.1051/e3sconf/202126202021