Aquarium filter media consists of three types, mechanical, chemical, and biological. Each type of media plays a role in aquarium filtration. Selecting the proper media for your fish tank will make a difference in its health and appearance. In part one of this three-part series, we review mechanical filtration, which is the first line of defense in an aquarium.
What is Mechanical Filtration Media?
Mechanical filtration media traps and removes particulate matter from the water column. Most reef tanks use some form of this filtration in combination with chemical and biological filtration.
Why Use Mechanical Filtration Media?
Mechanical filtration removes floating debris in the water, including fish food, fish poop, and other detritus. This is essential because If this debris is not removed, it will decompose and break down into toxic chemicals, like ammonia and nitrite, negatively impacting water quality. After the water passes through this filtration stage, it proceeds through other stages before being returned to the display tank.
Types of Mechanical Filtration Media
There are three main types of mechanical filtration, each with its own unique application. Therefore, choosing the proper type depends on your tank size and budget.
Filter Pads
Filter pads are rectangular or square-shaped pads generally made of polyester fiber. These pads are available in various thicknesses and porosities and trap floating materials as the water flows through them. Cutting filter pads to size allows them to work in smaller aquariums or external filters.
Filter Socks
A filter sock functions similarly to filter pads trapping particulate as the water flows through them. Cleaning filter socks allow them to be used continuously. Also, placing other forms of filter media inside the filter sock allows you to pack more filtration into a confined space.
Filter Rollers
A Filter roller is a lower maintenance alternative to filter socks. These units cycle through a long rolled-up filter pad eliminating the need to constantly clean and swap out your filter socks. That said, once the rolls are fully used, they will need to be thrown out and replaced with new ones.
Mechanical Filtration Comparison Chart
| Factor & Type of Media | Filter Pads | Filter Socks | Filter Rollers |
|---|---|---|---|
| Cost |  | | |
| Recommended Use | In a sump, all-in-one tank, or external filter | In a sump or all-in-one tank | In a sump either in addition or in place of a filter sock |
| Recommended Tank Size for Use | 5-55 gallons | 55+ gallons | 75+ gallons |
| Maintenance | Replace 1-2 per week | Replace 1-2 per week | Rotate roll at least once a week; replace roll as needed |
| Nutrient Removal | Suspended particles, detritus, and some organic elements | Suspended particles and detritus | Suspended particles and detritus |
| Other Considerations | In addition to removing detritus, some filter pads can also remove nitrate and phosphate. | Filter socks can be cleaned, dechlorinated, and reused multiple times. | Filter rollers are great for low-maintenance mechanical filtration. Regular replacement of the rolls is necessary. |
Mechanical filter media is your first line of defense in improving your water quality by removing particulate matter from the water column. Despite this, mechanical filtration media is just one part of the filtration puzzle. Stay tuned for parts two and three of this article, where we will complete the filtration media puzzle and take your water chemistry to the next level.
Please contact our support team if you have any additional questions or need a filter media recommendation.