The Biological filter
It is very important for every aquarium keeper to understand what biological filtration is.
The biological process is what happens in the home aquarium naturally after a month or so of the aquarium being set up. It is this system that will convert fish waste into less harmful products. If you disturb this process by washing filters with tap water and destroying the beneficial bacteria you will many problems with the water chemistry in your tank. If you work with and understand how your tanks biological filter works then you will know how to maintain it correctly.
In simple terms the biological filter is as follows:
When we feed our fish they produce waste which produces ammonia. Ammonia is also produced by dead plants and animal matter. The beneficial bacteria living in our systems will convert Ammonia into nitrite Ammonia is very toxic to fish and invertebrates, and high nitrite levels are not good for fish either. Nitrite is then further broken down into nitrate and nitrate is assimilated by algae, coral, mollusks and is only harmful in large quantities.
When we feed our fish they produce waste which produces ammonia. Ammonia is also produced by dead plants and animal matter. The beneficial bacteria living in our systems will convert Ammonia into nitrite Ammonia is very toxic to fish and invertebrates, and high nitrite levels are not good for fish either. Nitrite is then further broken down into nitrate and nitrate is assimilated by algae, coral, mollusks and is only harmful in large quantities.
This is a very simple explanation of how our tanks biological filter works but hopefully explains the importance of it. If you set up a new tank and place a lot of fish into then the bacteria required to deal with the fish waste will not have been formed yet. This will result in the fish waste creating high levels of ammonia because it can not be broken down yet. This in turn will kill your fish very quickly. It is why only a hardy single or couple of fish should be introduced into a new tank set up. They will help to slowly start the biological fish so that when other fish are added there is already an established biological filter.
Biological filters do not only occur in filter media but also in the substrate of an aquarium or pond. So when filters are cleaned and substrate they should be cleaned in a bucket of tank water so that the healthy bacteria is not killed off. Tap water contains chlorine and many other harmful substances to fish and will kill healthy bacteria in filter media etc if used, hence the need for cleaning filters in aquarium or pond water depending on what fish you are looking after.
Biological filters do not only occur in filter media but also in the substrate of an aquarium or pond. So when filters are cleaned and substrate they should be cleaned in a bucket of tank water so that the healthy bacteria is not killed off. Tap water contains chlorine and many other harmful substances to fish and will kill healthy bacteria in filter media etc if used, hence the need for cleaning filters in aquarium or pond water depending on what fish you are looking after.
