The right combination for every need


In an enclosed aquarium environment, toxic compounds can accumulate quickly. In fact, your fish never stop producing waste as they go about their day, therefore, continuous filtration is necessary to ensure their survival. It not only helps by removing harmful elements from the tank, but also traps debris, oxygenates the water and provides ideal surfaces for beneficial nitrifying bacteria to cultivate upon. A combination of mechanical, biological and chemical filtration media are required to help you achieve optimal water conditions. Let’s explore these in greater detail.


Removes particles and debris through mechanical strainers

Mechanical filtration does not alter water chemistry. Its main purpose is to trap and remove waste and debris (i.e. fish excrement, sludge, uneaten food, dust, etc.). Types of mechanical filter media include pre-filter cylinders, foams and polishing pads.

Mechanical filtration not only helps improve the overall appearance of your tank, but is also important for improving the efficiency of your filter’s biological filtration. While a mechanical foam or pad strains solids as water passes through, it also prevents such elements from reaching the biological media and creating dead spots (where bad bacteria can accumulate). Denitrifying bacteria, which is desirable, prefers higher oxygen levels and a clean surface upon which to colonize. Many undesirable bacteria species, on the contrary, prefer surface areas with a lower oxygen and high organic content.

For best results, place these pads at the last stage of filtration and replace frequently, or immediately after eliminating such particulates.

The most important thing to remember about mechanical media is that the smaller the pores, the faster it will clog. To prevent build-up in any situation, mechanical media should be rinsed regularly and replaced as directed – typically every few months for coarser sponges, or every 4-6 weeks for finer pads.

Mechanical media varies by the size of its pores, which essentially controls the size of the particles that get trapped. Fluval provides a coarse foam standard with all its filters to not only trap the majority of large debris, but to also support effective continuous water flow. When finer filtering is required, Fluval Polishing Pads trap even the smallest of particles, including silt or suspended algae.


When choosing mechanical filter media, make sure to consider the types of fish and how many you plan to keep. For larger species or greater numbers of fish, make sure to install a greater quantity of coarse mechanical media.

CHEMICAL Filtration

Actively changes water characteristics through deliberate chemical reactions

Chemical filtration removes pollutants such as chlorine, discoloration, tap water impurities and other dissolved waste materials through chemical reactions. It provides an extremely convenient way to maintain high water quality for an extended period of time. Types of chemical filter media include carbon, organic scavenging resins, peat, ammonia remover and zeo-carb.


Carbon is the most common chemical filter media used in aquariums and works by binding impurities to its surface as water flows through the filter. Carbon, along with other chemical media, will eventually become saturated and should be replaced every month or so under normal conditions, or immediately if used for an isolated case (i.e. removing residual medication or clearing discoloured water). Fluval manufactures granulated Activated Carbon, which offers a greater surface area for pollutant absorption versus extruded pellet carbons. It is also made with bituminous coal – the best possible raw ingredient for water filtration.


Always refer to Fluval filtration media packaging to guide you on replacement frequency. Chemical filtration media has a limited life span that renders it less effective the more it absorbs tank impurities over time.

Some carbons on the market are coconut shell based which, although ideal for air filtration, are not as effective for water filtration. Fluval Sea Total Clear provides the ultimate in chemical filtration by employing a higher-grade carbon, which is mixed with an organic scavenging resin, allowing it to react faster and with greater absorption capacity on a wider spectrum of impurities. Other forms of chemical filtration media can be used to solve common aquarium problems such as algae or high ammonia levels. Fluval Clearmax and Fluval Sea Phos Clear.


Ammonia is continuously introduced into your aquarium through fish waste, respiration and other biological processes, and is toxic if not kept in check. When ammonia levels spike in an aquarium (due to ammonia levels exceeding the capacity of existing beneficial bacteria), your fish will usually show signs of stress - erratic swimming behavior, laboured respiratory gasping, fin/skin damage, etc. Since biological load (i.e. the amount of fish you keep, how much your feed your fish) has a direct correlation to ammonia production, you want it to be ideally less than or equal to the nitrifying capacity of existing bacterial population . Fluval Ammonia Remover is recommended in this situation.


Some filter media, such as Fluval Zeo-Carb, include a 50/50 mix of ammonia remover and activated carbon to keep ammonia levels low, while removing molecules that discolour the water at the same time. This 2-in-1 product saves space in the filter and allows the user to load more media, if desired, to further improve water quality and clarity.


Fluval Peat Granules are another excellent filter media that will create and support a natural stained water condition, as well as lower the pH value favoured by many of the most popular tropical freshwater fish (i.e. neon and cardinal tetras, angelfish, discus, dwarf apistogramma cichlids). The natural, pollutant-free acids and tannins slowly released by Fluval Peat Granules will ensure that those species that prefer soft, acidic water will show their best colours, just as they would in nature.


Breaks down and eliminates toxins through bacterial action

Biological filtration is a natural action where bacteria will break down dangerous compounds into a less toxic form. This process, known as the Nitrogen Cycle, involves converting toxic ammonia into nitrite, and then into less harmful nitrate.

Biological media is used to cultivate and promote the growth of good bacteria that breaks down ammonia. Bio media is available in porous rock or pebble-like material, ceramic cylinders, plastic balls, coarse mesh-like material, or even in slab form.


Biological filtration relies heavily on oxygen levels, most easily achieved with proper water movement at the surface. Bio media is normally placed in your filter where water brings nutrients and oxygen to the bacteria, thereby allowing them to complete the nitrogen cycle. It’s recommended that your mechanical media should filter particles from the water before it reaches the bio media. This will help impede any build-up or clogging from occurring.

Fluval Bio Max Rings allow water to pass freely around and through its hollow body. This provides maximum surface contact with the intricate porous material, upon which denitrifying bacteria can easily grow. Water quality improves dramatically as a result, and becomes more stable even if fish load or other factors change.


Always rinse biological media in water taken from your aquarium when cleaning and maintaining your filter. This will prevent chlorinated tap water from destroying the beneficial denitrifying bacteria. Fluval Biological Enhancer can be poured directly onto this media when loading and setting up to help inoculate your tank with good bacteria.

Once beneficial bacteria are established in your bio media, they are able to adapt to increased biological demands fairly rapidly. Be mindful as they can also be depleted by over-cleaning or coming into contact with untreated chlorinated water and certain medications such as antibiotics. Fortunately, Fluval offers a wide variety of effective water conditioners can be used in combination with your filter media to help stabilize all types of aquarium environments.

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