the aquaponics systems use the available fish water that is rich in fish waste as nutrients for plant growth.
Another advantage of this combination lies in the fact that excess of nutrients does not need to be removed through periodical exchange of enriched fish water with fresh water as practiced in aquaculture systems
The system results in a symbiosis between fish, microorganisms and plants, and encourages sustainable use of water and nutrients, including their recycling (Figure 1).
Within this synergistic interaction, the respective ecological weaknesses of aquaculture and hydroponics are converted into strengths.
This combination substantially minimizes the need for input of nutrients and output of waste, unlike when run as separate systems.
the concentrations of micro- and macronutrients need to be monitored. Periodically some nutrients may need to be added to adjust their concentration, for example iron is often deficient in fish waste [24,25].
Aquaponic systems need to be able to host different microorganism communities that are involved in fish waste processing and solubilization. Ammonia (NH4+) from fish urine and gill excretion can build up to toxic levels if not removed from the system.