A Recirculating Aquaculture System (RAS) represents an intensive aquaculture practice designed to minimize water changes by recirculating water, thereby ensuring optimal water quality for high-quality fish production. At the core of RAS is the biofilter, responsible for converting ammonia into nitrate through nitrification, contributing to the maintenance of favourable water conditions for fish culture. Azolla pinnata , a floating aquatic fern, serves as a phytoremediator in wastewater by assimilating inorganic nitrogen. As such, A. pinnata can serve as an additional biofilter in RAS, with added benefits for the agriculture industry as livestock feed.
This study aims to (1) measure the growth performance of A. pinnata in RAS and (2) assess the water quality in RAS with A. pinnata (RAS + AP) against RAS without A. pinnata (RAS - AP). Results from the experiments reveal a notable increase in biomass for A. pinnata within the RAS environment compared to a controlled setting. Meanwhile, the water quality in both (RAS + AP) and (RAS - AP) exhibits no significant difference (P > 0.05).