Mechanical filtration in an aquarium is the removal of particles the hobbyist can see. These particles include fish feces and uneaten food. This is what most beginners think is the most important type of filtration. It is relatively unimportant.
Filtration should be looked at from a chart.
| Water contaminant | Biofiltration | Mechanical filtration |
Most chemical filtration |
Ultraviolet |
|---|---|---|---|---|
| Ammonia and nitrite | Removes | |||
| Bad bacteria | Removes | Removes | ||
| Pathogens like ich | Removes | Removes | ||
| Dissolved organics | Removes | |||
| Feces, uneaten food | Removes | Removes | ||
| Floating algae | Removes | Removes | Removes | |
| Tannic acid, dyes, smells | Removes |
Obviously, biofiltration is easily 80% of the game here and mechanical filtration is relatively unimportant.
There are two types of mechanical filtration systems:
- “Cleaned Mechanical Filtration” – mechanical filtration cleaned frequently
- “Uncleaned Mechanical Filtration” – mechanical filtration never or rarely cleaned (this might more accurately be termed “no mechanical filtration”)
Both these mechanical filtration systems are perfectly acceptable and can work well.
ALL filter media act as mechanical filters. They just act at different levels. Small particles of food and feces will be “stuck” to any filter media surface. The more surface area a filter media has the better it functions as a mechanical filter. While some bioballs or ceramic rings might only have 10% of the mechanical filtration of say a pinkie pad, a piece of 30 ppi foam might be 70% as effective as a pinkie pad. But the foam is most importantly a biological filter so the mechanical filtration by foam must be “uncleaned” mechanical filtration.
There are some aquarium hobbyists who are interested in delving deep into the science and the calculations behind all aspects of the hobby. For those who are so inclined, the following is pertinent:
6.1.1. Cleaned Mechanical Filtration
6.1.2. Uncleaned Mechanical Filtration
Startpage Aquariumscience
Source: Aquariumscience.org – David Bogert
