Each of plant growth bed unit and fish-rearing tank had 10 air diffusers (2 Lmin−1), which were cleaned monthly. There were also three air diffusers in the degassing tank. Settleable solids were removed from the clarifiers one time daily by opening a ball valve.Fine solids were collected by netting plastic screens in the filter tanks and were removed two times monthly by draining the tank and washing the netting. There was also a plastic screen at the entrance of degassing tank which prevented fish fry to reach to
the hydroponic tank.