Filter Media & NItrification
The main reason why your aquarium water should be filtered over a medium is to establish an increased bacterial culture which can help to break down ammonia. Ammonia is made up of nitrogen and nitrogen and is a toxic strong alkaline gas that kills life. The ammonia and nitrogen degradation process is called nitrification. The so-called nitrification process is part of the global nitrogen cycle and is usually divided into two chunks. First, one group of bacteria converts ammonia to nitrite, which is then converted to nitrate by another group of bacteria. However, a group of newly discovered bacteria can perform the entire process alone. That understanding has changed the basis of how scientists think about the turnover of nitrogen.
The largest conversion of ammonia on the planet takes place in our open oceans. There is thus also a significant nitrification in the aquarium water, which should not be underestimated.
The process looks like this:
Proteins from dead cells and waste products -> microbial degradation -> amino acids -> microbial degradation -> ammonia (NH3) -> NH3 + H2O -> NH4 + + OH-
The next sequence of reactions in the nitrogen cycle involves oxidation of nitrogen in the ammonium ion to form nitrate. In the aquarium live autotrophic nitrifying bacteria, such as the genera Nitrosomonas and Nitrobacter. These microorganisms, extract energy by oxidizing ammonia or nitrite. In the first phase, Nitrosomonas oxidizes ammonium to nitrite:
NH4 + -> Nitrosomonas bacteria -> NO2-
In the second stage, such organisms as Nitrobacter oxidize nitrite to nitrate:
NO2- -> Nitrobacter bacterium -> NO3-
We know today that nitrate is toxic in large quantities to freshwater fish. Danish tap water has a maximum limit of 50mg per liter. However, tropical aquarium fish generally tolerate much lower concentrations and several species are particularly sensitive because tropical rainforest water does not contain nitrate at all. Among these, discus, as experience has shown, does not thrive with a nitrate content above 15 mg / liter and preferably below 10 mg / liter.
Natural biological filter materials unconditionally create the best conditions in an open ecosystem. But, in a closed biotope, as an aquarium is, the balance between success and failure, on the other hand, is fiercely fine. The best results are obtained by using the filter media that nature has used for millions of years. You get clear and healthy water with a minimum of harmful substances and your fish will thrive and show their full color splendor and behavior. These media, typically long-lived sphagnum, are cumbersome to deal with and decay relatively quickly, creating instability, so secondary inorganic filter materials, with the largest possible surface for bacterial colonization, may be preferable, depending on need, physical environment. and opportunities.
Sintered glass and ceramics have the absolute largest surface in terms of volume and will, under the right conditions, always be the best and cheapest choice in the long run. Plastic materials, such as K1 Kaldness, are popular, but probably mostly due to the relatively lower cost, compared to the ceramic products. Saving can often be a bad idea, as a larger volume filter requires more pumping capacity and everything else being equal, also more time for maintenance. The difference in, for example, power consumption can quickly reach 30W per hour or over 250Kw / year, which for most means an expense of over 500 DKK!
The topic is large and it is difficult to get around briefly with an overall overview. You will find a scientific article that tests 3 different basic types of filter media under Reading material here on the webshop and you can read specifically about our recommendation on a simple but extremely effective filter [HERE]. You will also find a detailed explanation of the advantages and disadvantages of the individual filter media when you look through the product selection!