Hello dear friends. So it’s time to get acquainted with such a wonderful device for the aquarium as a biofilter.
In today’s material we will find out why it is needed and understand its design features. In addition, we will review the main biofiltration processes that take place in aquarium filters and find out how the filter device will affect biofiltration as a whole.
To begin, let’s determine the purpose of this device. Biofilters carry out chemical, biological and mechanical filtration of aquarium water. As you know, aquarium filters are external and internal.
In turn, the external filter is often called a canister or biofilter. Due to the possibility of installing inside the canister filters a large number of various filtering fillers and various devices, the quality of mechanical and biological water purification in the biofilter is significantly improved.
Water purification is divided into mechanical and biological. During mechanical cleaning, water is cleaned from mechanical suspensions, that is, from bottom sludge, sand, dirt, remnants of rotted plants and other things.
Biological filtration is commonly understood as the process of processing organic compounds that is in a dissolved state and this is done with the help of colonies of beneficial bacteria that settle in canister filter media.
The main chemical element that ensures the flow of biological filtration in an aquarium is oxygen. It is necessary for bacteria, which they secrete from the water passing through the aquarium filter.
If the flow of water through the filter to stop, then the colonies of beneficial bacteria will die from lack of oxygen. The biofiltration process proceeds as follows: organic compounds, which are contained in almost all waste products of aquarium inhabitants and plants, during decomposition increase the amount of ammonia / ammonium, then ammonium / ammonia is split into nitrite, and then into nitrate.
I described this process in more detail in the article “Nitrate cycle in an aquarium”.
Naturally, the process itself is much more complicated, but this information is enough for the general development of a beginner aquarist. The meaning of biofiltration for aquarium fish is that fish waste is decomposed into less toxic forms. Of all the above forms, nitrates are the safest for aquarium fish.
And to reduce the concentration of nitrates in the aquarium, you can use another water change for fresh.
Kohl, we have dealt with the basic concepts of biological filtration, now let’s start exploring the design features of those same canister filters. Most of the external (canister) filters, examples of which are examined in today’s material, are constructively divided into several compartments, through which aquarium water is passed during the course of biofiltration. There is a generally accepted standard in the market for the location and purpose of these compartments:
- Compartment with ceramic rings, in which water will flow in the first place. Thanks to these very rings, the injected flow of water is broken about them and is evenly distributed throughout the compartment, where the primary and fairly rough mechanical purification of water is carried out, in which large debris and organic suspension is eliminated.
- Behind the first compartment with ceramic rings, a compartment with biospheres or other similar fillers is installed, with a large surface area and a finely porous structure. In such fillers and find a haven a huge amount of beneficial bacteria, carrying out the process of biofiltration.
- The third compartment in the canister filter is a compartment with a filler for fine cleaning. To do this, inside the third compartment placed several sponges with different porosities. In addition to the sponges, activated carbon is placed in the same place, which performs additional water purification. Since coal is not eternal and needs to be changed periodically, aquarists use it only temporarily. At the third stage, water is filtered from residual suspensions, debris and other nastiness that remained in the filtered water.
The above scheme is typical for most external filters, which are widely distributed in the market of aquarium products. Clearly, the differences in the devices will always be, but the general principle remains the same.
As a rule, such filters vary in size, shape, power and types of fillers. Also in some models you can find fewer or more compartments in which you can put non-standard fillers such as chemical reagents designed to neutralize ammonium, ammonia and nitrite.
Recently, universal external filters have begun to appear on the market, in which additional devices are built in, such as a heater, aerator and UV sterilizer. But at the moment such devices are not in wide demand, so far.
However, progress on the spot is not worth it and literally some two or three years, such filters will be found in almost every specialized store.
That would be all that I would like to say about external filters or so-called biofilters. But a little bit I would like to focus your attention on the mode of the device. As I mentioned above, the filter must be constantly plugged into the network and drive water through itself, otherwise all colonies of beneficial bacteria will die from lack of oxygen.
If you turn off the device for a long time, the dead bacteria form a harmful biomass, which is not the place in the aquarium. The maximum interruption in the biofilter should not exceed 20 minutes.
If the device has stayed longer than the specified time, then you will need to rinse the fillers and the device itself well. And when you turn on the filter in the network, it will take from several days to several weeks for the colonies of useful bacteria to settle in the fillers.