FILTRATION
Arguably, the most important piece of equipment in a fish tank is the filtration, they are not optional and they are not substitutional. Filters are the engines of your aquarium; without them, keeping your fish alive would be nearly impossible.
* The media illustrations used when discussing the different types of filtration is for illustrative purposes only. For example, filter sponge will act as a mechanical and biological filtrate because bacteria will live within it, while particulate matter and debris will be trapped by it.