But not only plants and fish integrate the ecosystem into our aquariums, there are inhabitants not as visible but indispensable as bacteria. aerobic bacteria transform debris into fertilizer for plants. Debrites are the result of food not consumed by fish, excrement and dead algae or fish. But the considerable thing is that the same bacteria consume 30 times more oxygen per gram of matter than fish. This is why the urgent need for adequate oxygenation of water and the recommendation to avoid overcrowding of fish tanks.
In aquariums or fish tanks, oxygen reaches the water in 2 ways: + The first is the absorption of oxygen present in the air from the surface of the water. + The second route is the photosynthesis performed by plants during lighting hours.
It should be noted that most oxygen arrives in the first way, while that of photosynthesis becomes secondary. The reality is that the larger the area or surface of contact between water and air, the greater the oxygen exchange. This shows that an aquarium is not a completely closed system. In fact, if the oxygen demand of fish, plants and bacteria does not exceed the absorption capacity of the surface of the fish tank, the aerator is not necessary. Even its function in the biological filtering can be replaced with a small internal pump.
Fish of very warm waters are the least benefited from this condition, since one of the main factors influencing the concentration of oxygen in the water is temperature. There is an inversely proportional ratio, that is, the higher the temperature the lower the concentration of oxygen in the water. This is because when the temperature rises, the solubility of the gas decreases, ergo, it is more easily detached.
Another factor of incidence is atmospheric pressure. In this case, the ratio is directly proportional; the higher the pressure the higher the concentration of oxygen. The lighting of the aquarium is also a factor. From it will depend the amount of photosynthesis performed by plants, and of course, the amount of oxygen resulting from such a process. But not only plants are affected by lighting, since it also influences the processes of decay of organic substances, carried out by aerobic bacteria.
Whenever the ecosystem demands more oxygen than the surface exchange can provide, we will need to provide oxygen by external or artificial means. It is useful to know that the amount of air that can be contained in the liquid medium is very low. In a unit of volume of water, barely five percent of the oxygen that can be contained in a unit of volume of air can be contained. Know also that the regime of oxygen diffusion in the water, is several thousand times less than in the air.
The use of the aerator is often misunderstood, since its bubbles almost do not provide oxygen directly to the water, but do so indirectly. Below we will explain the process of oxygenation of the water using the aerator.
© Adrián Blanco 2005 — Prohibited the total or partial reproduction of text and/or images without explicit written consent of the author. —