Best Aquarium Filter Media Guide, Setup And Maintenance

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Almost aquarium filters today use mechanical, chemical and biological filter media for the most performance. They are the best filter media used to perform 3 types of filtration mechanical, chemical and biological that keeps aquarium water clean, clear and non-toxic for your fish and shrimps. In this article, I will provide you all you need for choosing filter media as well as how to set up and maintain them.

Mechanical Filtration And Filter Media

What Is Mechanical Filtration And How Does It Work?

Mechanical filtration uses mechanical filter media to capture of particulate matter from the aquarium water. Mechanical filter materials can capture solid waste such as decaying plants and animals, uneaten fish food and fecal waste that keeps aquarium water clear.

Moreover, mechanical filtration is very important with a filter system because it reduces the load on biological filtration, chemical filtration. They are the mechanism behind any aquarium filter and work together to efficiently remove all contaminating factors out of the water as you can see in the previous picture.

Best Mechanical Filter Media

There are many types of mechanical filter media such as floss, foam (sponge), pre-filter media… that you can easily buy online or any pet stores. Besides, it’s very easy for you to do a mechanical medium by yourself.

Thick and  Durable - Editor's Choice
  • Lightweight and softness design. 
  • Excellent water permeability.
  • Dense shape makes it effective to avoid residue. 
Fine Fibers - high quality
  • Easy to cut to fit and change
  • Allows for proper water flow in your filter
  • Catches detritus in Aquariums, Ponds and Terrariums
Good Price and Quality - Best Value
  • Captures solid waste
  • Works to prevent filter clogging
  • Helps reduce the replacement of filter media

How To Set Up Mechanical Filter Media

They can be used by packed in a filter such as canister filter, power filter and other aquarium filter types. If your aquarium has a Wet/Dry sump filter system, you can run the water draining into the sump through a chamber of filter floss or similar material or through a specially designed filter sock.

Some hobbyists prefer using aquarium skimmers to do this works rather than using mechanical filters. They are very effective in removing particulate matter and, in many ways, can take the place of mechanical filters.

How To Maintain Mechanical Filter Media

One key point when using mechanical filters is that they need frequent cleaning. If a mechanical filter is not cleaned regularly, the material it collects, with a constant stream of water running through it, will decay, and then the mechanical filter will increase the load on the biological filter rather than decrease it.

Detritus left to decay in some quiet corner of the tank will release any nutrients that it contains very slowly. Take the same detritus, trap it on some filter media, and force oxygenated water through it, and it is likely to break down and release its nutrients much faster. So cleaning the mechanical filter media is an important work to keep the water clean and safe for your fish.

When your filter materials are too old, you need to change the new ones. Using pre-filter media can reduce the replacement because you can clean and reuse them many times than a floss or foam.

Good Price and Quality - Best Value
  • Captures solid waste
  • Works to prevent filter clogging
  • Helps reduce the replacement of filter media

Biological Filtration And Bio Filter Media, Bio Max

What Is Biological Filtration And How Does It Work?

Aquatic animals (fish and invertebrates) excrete nitrogenous wastes, which is highly toxic in an aquarium; and biological filtration using living organisms such as bacteria, algae detoxify those wastes by converting them from ammonia to nitrite and then nitrate (a process called nitrification).


Nitrogen cycle and biological filtration in aquarium

Briefly, biological filtration is the process of using living organisms (usually bacteria) to remove waste products, particularly nitrogenous compounds. The nitrification process is what classic biological filters are designed to do. They pump oxygen-rich aquarium water over substrates on which nitrifying bacteria can grow. Besides, the incoming water pre-filtered with mechanical filter media will provide nitrifying bacteria with clean and oxygen-rich surfaces that promote their activities.

Best Biological Filter Media

Biological filter media provide the best mini houses for nitrifying bacteria to colonize. The best biological filter materials are Ceramic Rings (a well-known product is Bio Max from Fluval), Fluval Zeo-Carb, Fluval Ammonia Remover, Bio-Media, Bio-balls…

Very Effective Filter - Recommended
  • Provides superior bilogical filtration
  • Replenish only half at one time to allow proper seeding
Completely natural - Good Quality
  • Never needs to be replaced
  • Enables higher stocking levels
Small Foam - Best Value
  • do not require replacement
  • can promote gas exchange, 
Filters That Last - Recommended
  • Enhances biological filtration
  • Effectively captures small particles and debris
  • Adds a second layer of mechanical filtration

The Fluval Bio-Foam can play roles as both mechanical and biological filter media.

How To Use Biological Filter Media

Biological filtration is the natural mechanism behind the simple sponge filter and undergravel filter. In other filters such as power filter, canister filter, trickle filters and fluidized sand beds, biological filter media need to be supplied to perform the filtration.

Biological filters need to be cycled or matured prior to stock the aquarium because the bacterial population needs to be large enough to handle the waste output of the first inhabitants. This is the reason why your new fish tank needs to be cycled before adding more fish.

This cycled or matured tank ready for stocking is usually done by adding a source of ammonia to the aquarium water and either waiting for bacteria in the environment to colonize the filter media or adding a starter culture. Ammonia and nitrite levels are then monitored.

First ammonia levels drop and nitrite levels rise (as the bacterial population that converts ammonia to nitrite becomes established), then the nitrite level drops as another population of bacteria flourishes and converts the nitrite to nitrate. At the point where both ammonia and nitrite levels are zero, bio-filtration is established and the process of stocking the aquarium can begin.

How To Clean Biological Filter Media In The Right Way

  • Open the filtration system (filter) and check if the bio filter media are dirty. Conduct maintenance of the filtration system in case of excessive build-up of sludge.
  • Pour aquarium water from aquarium tank into a pail. Be sure to rinse the bio filter media with aquarium water from the same aquarium tank to minimize the damage to microorganisms in the filter media.
  • Put the filter media in the aquarium water.
  • Lightly rinse the filter media by hand, avoid washing the filter media too hard. Rinse off the brown sludge gently by hand.
  • Reinstall the cleaned filter media to the filtration system.

Chemical Filtration And Filter Media, Fluval Carbon

What Is Chemical Filtration And How Does It Work?

Dissolved organic compounds can affect light transmission through water, giving it a yellowish tint; this can affect the growth and coloration of corals. Water changes also help to manage levels of dissolved organics, but to be most effective, a routine of regular water changes must be implemented from early in the tanks life.


Yellowish tint aquarium water

While biological filtration processes nitrogenous wastes very effectively, other types of waste products also accumulate in aquarium water. Skimming reduces levels of some dissolved organics but doesn’t remove all such substances.

Chemical filtration helps to remove dissolved organics that remain after skimming, biological filtration and water changes. These include a wide range of dissolved organic compounds, some of which contain phosphates, which are major algae nutrients and can inhibit the growth of stony corals.

Best Chemical Filter Media

There are many types of chemical filter media that can be used to remove phosphates or nitrates. Activated carbon is probably the most widely used chemical medium for chemical filtration, as it adsorbs a wide range of dissolved substances.

No Fabric - Editor's Choice
  • Improves water clarity and color
  • Effectively removes heavy metals, odors, discolorations
For Freshwater & Saltwater- Recommended

The Fluval Carbon, a well-known chemical filter media can remove liquid wastes such as urine, dyes, and impurities. Besides, it improves the clarity, color, odors and effectively removes heavy metals from the aquarium water.

The Fluval Clearmax Phosphate Remover traps phosphate, nitrate, and nitrite. Besides, it also reduces odors, provides crystal clear water that makes maintenance easier.

How To Use These Chemical Filter Media

Carbon can be used in a number of ways. If highly efficient chemical filtration is desired, carbon should have a strong flow of water through it. This can be achieved by placing it in an internal or external power filter or in a reactor fed with water by a pump. Another method is to place the carbon in a media bag and place this in a sump or a discreet place in the aquarium. Used in this way, the carbon has water flowing over it but not forced through it— this can be termed passive use of carbon.

Most other chemical filtration media (for example, phosphate removers) need to be used either in power filters or reactors with a strong flow of water through them to be effective. In some cases, fluidized reactors may be used to increase the efficiency of adsorption.

How To Maintain The Chemical Filter Media

Unlike biological filtration, chemical filtration works by binding dissolved substances to media to remove them from the water. There is no chemical processing of those substances into less harmful compounds. This means that eventually the media will become saturated and will need to be replaced.

While synthetic media that are saturated will usually simply stop to trap more waste products, carbon is more problematic in that when saturated, it can start to dump adsorbed substances back into the water. For this reason, it’s important to change carbon on a regular basis; somewhere between every month and every three months seems to work well. You shouldn’t clean and reuse the carbon media.

Many hobbyists like to use carbon in two or more media bags within their systems so that part of the carbon can be changed at any one time. This reduces the possibility of a sudden large increase in the adsorption capacity in the system causing a rapid drop in dissolved organics, as could occur if all the carbon were changed at once.

One question that is worth asking about chemical filtration is whether your aquarium really needs it. If your tank has an efficient skimmer and you perform frequent partial water changes, the answer may well be no, particularly if the system is only lightly stocking.

Affiliate links & Images from Amazon Product Advertising API. Last update on 2022-09-11.

Top Editor's Choice on Aquarium Filter Media

SaleBestseller No. 1
API QUICK START Freshwater and Saltwater Aquarium Nitrifying Bacteria...
Allows instant addition of fish when starting a new aquarium; Reduces compounds harmful to fish when used routinely
SaleBestseller No. 2
Tetra Whisper Bio-Bag Filter Cartridges For Aquariums - Unassembled
CATCHES DEBRIS Dense dual-sided mesh filters debris and fish waste; CONVENIENT Easy to assemble and easy to replace
SaleBestseller No. 3
Marineland Rite-Size Cartridge C, 6-Pack
Chemically filtered through Black Diamond Premium Activated Carbon.
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Aqueon Replacement Filter Cartridges Medium - 6 pack
Cartridge contains high quality activated carbon that keeps water clean; Easy installation using the "FRONT" orientation tab
SaleBestseller No. 6
Tetra ReptoFilter Cartridges - Medium 3 pack, green (25845)
DUAL-SIDED MESH: Catches debris and waste to keep water crystal clear; CONVENIENT: Disposable, fully assembled and ready to use
SaleBestseller No. 8
FairmountSantrol AquaQuartz-50 Pool Filter 20-Grade Silica Sand 50 Pounds,...
Ecologically safe sand does not solidify and will help prevent clogging and channeling; 100% natural sand is chemical free and backwashes easily and evenly
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E-Cloth Glass Cleaner, Window Cleaning Kit, Premium Microfiber Window...
Eco-savvy — Just wet, wipe away, rinse and reuse. It's as simple as 1,2,3!

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