Biofiltration

Another concept that I am not about to leave out is Oxygen, more importantly, it's availability for your fishes and the nitrifying bacterial colonies. Availability is directly proportional to the air-water interface where most gas exchange occur. Increasing temperature and dissolved organic compounds will decrease the availability of Oxygen.

One can increase the availability of Oxygen in practice is to enlarge the air-water interface - aeration with the production of air bubbles (more bubbles means more surface area for the air-water interface), providing a larger surface area at the water level (rectangular fish tanks will have more than a square or round one) or increasing the rate of gas exchange by increasing the flow on the water surface.

More to follow....