While mechanical filtration is used to remove particles from the water, biological filtration is the bacteria breaking down harmful chemicals such as ammonia, such as was described in The Nitrogen Cycle at the beginning of this section. While it is extremely important to clean the mechanical filtration system of your discus tank regularly, you will want to leave the biological filter alone to do its job.
There are many different kinds of biological filters available on the market today such as canisters, the trickle filter, the simple box filter, the fluidized bed bio filter, and many many others.
Because there are many different kinds of biological filters, there are many different kinds of components to the biological filters as well. Some of these components include: plastic hair curlers, “bio beads”, gravel, sand, sintered glass and ceramic noodles.
Biological filtration is crucial to the well being of not only your discus fish but also of your discus aquarium. Whichever method of biological filtration you are considering using, you need to remember to take proper care of it, and prevent the nitrifying bacteria from coming to harm.
It is important to note that it takes just about six weeks for nitrobacteria to properly set themselves up in the filter. During this time it will be very easy for the nitrite and ammonia levels in your discus tank to reach dangerous levels. To help avoid this the best case scenario is to simply set up the tank six weeks prior to getting your discus fish. If however, that is not an option for you, remember that in this crucial stage not to overfeed your discus, and to keep the number of discus fish in your discus aquarium down to a minimum.
The water in the tank may cloud over in this period while the nitrifying bacteria is setting up. This is known as the “new tank” syndrome, this is a normal occurrence and will clear itself up rather quickly, once the nitrifying bacteria have had a chance to get set up properly.
It is of extreme importance that when you are cleaning the biological filter of your new discus aquarium that you only use tank water to clean it with, and don’t use any soaps, cleaning agents or hot water, which could potentially kill off the nitrifying bacteria in the filter.
If for whatever reason your discus aquarium goes for a bit without electricity, it could be possible that you will need to resupply your nitrifying bacteria, as without oxygen or food they will die off. The amount of time can vary depending on a number of things, however, if the power has been off for a day, and your fish are gasping for air, don’t turn the filter back on as it is likely become toxic. You will need to completely clean the filter, this time using hot water, soap and cleaning agents, and then resupply the bacteria all over again.