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.