Nitrifying microorganisms in inoculum for RAS biofilter

A recirculating aquaculture system (RAS) for rearing Atlantic salmon requires nitrifying microorganisms in the biofilter for ammonia removal in order to be fully functional. These microorganisms are time-consuming to establish in the biofilter due to their slow growth rates, and a good biofilter activation strategy is therefore necessary for an improved and short maturation period of biofilters in new RAS. In this study, biofilm establishment and nitrifying efficiencies by two different inoculums were compared using growth experiments that simulated activation of new RAS biofilters.