Nutrient removal is essential for aquaculture wastewater treatment to protect receiving water from
eutrophication and for potential reuse of the treated water. The integration of aquaculture with agriculture
appears to be an excellent way of saving water, disposing aquaculture wastewater and providing
fertilizer to the agricultural crop. The study was conducted to evaluate aquaponics recirculation
system (ARS) performance in removing inorganic nitrogen and phosphate from aquaculture
wastewater using water spinach (Ipomoea aquatica) and mustard green (Brassica juncea). The results
showed that water spinach was able to significantly reduce the total ammonia nitrogen, nitrite-N,
nitrate-N and orthophosphate with efficiencies of 78.32–85.48%, 82.93–92.22%, 79.17–87.10%, and
75.36–84.94%, respectively, compared to mustard green that removed the nutrients in the range of
69.0–75.85% for total ammonia nitrogen, 72.49–79.34% for nitrite-N, 66.67–80.65% for nitrate-N, and
66.79–77.87% for orthophosphate. Overall results suggest that water spinach is better than mustard
green in nutrient removal in the aquaponics system used due to its root structures provided more
microbial attachment sites, sufficient wastewater residence time, trapping and settlement of suspended
particles, surface area for pollutant adsorption, uptake, and assimilation in plant tissues.