How to Install Fish Tank Filter Cartridge? – 10 Easy Steps

how to install fish tank filter cartridge

Like many newbies to a particular endeavor, first-time aquarists have many questions, including how to install fish tank filter cartridge in their respective aquariums.

Although the answer is fairly straightforward, everything depends on the aquarium filter setup. For instance, most newbie aquarists are familiar with a sponge and under gravel filter (UGF) because these are common.

Unfortunately, at least three major classes of aquarium filtration systems are available, making installation a bit complicated. Consider this article your handy guide for effective fish tank filter installation.

Different Types of Fish Tank Filter Cartridges


Knowing the aquarium filter type will help determine which way does the filter go in a fish tank. Aquarium filtration systems can fall into one of three categories – mechanical, biological, and chemical.

1. Box filters – The versatile corner filter is a favorite of aquarists because they can fill it with various filter media. However, these systems are only advisable as a small fish tank filter cartridge (<10-gallon aquariums).

2. Canister filters – Almost identical to box filters but designed for larger aquariums (>40 gallons). They have mechanical, biological, and chemical filtration.

3. Fluidized bed filters – These systems promote beneficial bacterial growth, allowing microorganisms to break down nitrites and ammonia into fish-friendlier nitrates.

4. Sponge filters – These filters are the most straightforward to install, and they work by mechanical and biological filtration.

5. Trickle filters – Exposing the aquarium water to air allows these filters to facilitate bacterial growth, allowing them to manage fish wastes without losing bacteria.

6. Under gravel filters – This type houses waste under a filter plate and uses a pump and tubes to move debris around. Many aquarists prefer this filtration system because it is effortless to set up and maintain. It is affordable, too.

7. Power filters – These filters feature simultaneous biological, chemical, and mechanical filtration.

Step-by-step to Install Fish Tank Filter Cartridge

What to prepare

Regardless of type, an aquarium filter replacement already comes as a kit. However, some products might require additional materials, such as cotton, ceramic, polyurethane foam, and rocks. It will be wise to buy a complete kit. Always inspect the filter kit before installation.

Step 1: Prepare the fish tank.


Avoid stressing your fish by installing the filtration system in a stocked fish tank. Many fish species are skittish and do not like disturbances in their ecosystem.

Ideally, you will want to change filter in fish tank without any living organisms, including fish, other aquatic life forms, and plants. Dipping your hands in the aquarium with these creatures might injure or stress them.

Prepare another tank or a large clean basin as a temporary shelter for your fish and plants. Transfer some water from the fish tank to the temporary container to help your fish adjust faster.

Carefully scoop each fish with a net and transfer them to their short-term “home.” Do the same for the plants.

Alternatively, you can coral your fish into a large plastic bag filled with aquarium water.

Step 2: Read the aquarium filter installation manual.


Although installing a filtration system is straightforward, we recommend reading the manual for specific filter for fish tank instructions.

It is worth noting that some aquarium filtration systems require correct assembly to ensure proper functioning. Connecting a component to the wrong port might cause problems in the fish tank, or the system will not work.

Manufacturers might also have recommendations on the optimal setup, including the best location and position in the fish tank.

Step 3. Plan the aquarium filter position and location.

This step should not be a concern if you read the instructions for fish filter replacement or installation.

For example, the best location for a canister filter is under the aquarium or behind the fish tank stand. Meanwhile, power filters are best “hanging” on the aquarium’s rear panel.

However, your setup might be different, requiring another approach. Examine and analyze your fish tank to determine the best possible location and position.

Some filtration systems require an outside-the-tank installation, while others need setups in the water (inside the tank).

Avoid placing the submersible water filtration unit in areas where fish love to “rest” or “hide.”

Step 4. Install the box filter


You are now ready to put filter cartridge in fish tank. Hopefully, you read the manual or installation instructions to know how to position and set up the various aquarium filtration parts.

Inspect the box and components for defects.

Fill the box with filter media. For example, you could use pumice stone, bio rings, or charcoal. You may also combine different biological media and add filter floss on top of them. The customization is in your hands.

Assemble the box filter, including the airline and other components. Connect the tube’s other end to an air pump and slowly submerge the box filter into the fish tank.

Step 5: Instal a canister filter


Notice the different filter media (i.e., mechanical, biological, and chemical) in the canister. After all, you will still need to change filter cartridge in fish tank once they clog up or lose their filtration capabilities.

Position the canister filter behind or underneath the aquarium stand. Ensure the canister is lower than the fish tank to allow gravity to filter the water.

Place an elbow on the aquarium’s upper edge to secure the inlet and outlet hoses. Position the stop valve on the canister filter’s top surface and connect one hose to the “IN” port. Dip the tube’s other end into the fish tank and secure it with the elbow.

Connect the tubing to the hose in the aquarium to extend the intake system to the fish tank’s bottom.

Connect another hose to the canister filter’s “OUT” port and secure the other end to the fish tank’s side opposite the intake hose.

Rinse the filter media and put them into the canister. Secure everything.

Step 6: Install a fluidized bed filter


Setting up a fluidized bed filter is a cinch in established aquarium units.

Assemble the filter by adding biological media and other filtration mechanisms. Attach suction cups to the filter’s sides.

Connect an airline to the filter’s port. Plug the airline’s other end into an air pump.

Submerge the fluidized bed filter into the fish tank and secure the suction cups on the aquarium wall. Plug the air pump into a socket.

Step 7: Install a sponge filter


Sponge filters have a strainer inside its foam sponge. This plastic strainer has a “bullseye” cap that snaps into place. Remove the sponge and the bullseye before inserting an air stone in the strainer.

Secure the air stone to the bullseye’s center or nipple with airline tubing. Alternatively, you can link the air stone to the bullseye.

Reposition the bullseye cap, put the foam over the strainer, and secure the strainer on the base. Insert the lift tube over the airline tubing and link it to the bullseye nipple. Ensure the lift tube forms a seal over the bullseye.

Submerge the sponge filter in the aquarium water.

Step 8: Installing a trickle filter


Assemble the trickle filter with your preferred media (i.e., a combination of porous rocks, bio balls, and fine/coarse foam filter).

Secure the drip tube over the filter media and connect one end to a flexible hose. Cover the trickle filter. Secure the tubing’s other end to a submersible water pump.

Position the water pump in the fish tank and place the trickle filter on top of the aquarium. Plug the water pump.

Step 9: Installing an under gravel filter (UGF)


Empty and clean the fish tank before installing a UGF system.

Connect the bubbler tube to the baseplate port and link an airline hose to the bubbler before inserting the bubbler through the housing tube. Connect the airline tubing’s other end to an air pump.

Position the baseplate on the aquarium floor and cover it with a fish tank substrate measuring two inches deep. Add décor and accessories and fill the aquarium with water.

Turn on the air pump and reintroduce your fish.

Step 10:  Instal the power filter


Setting up this aquarium filter is easy.

Secure the filter pump to the filter housing and connect the lift tube to the corresponding port on the housing.

Prepare the filter media and insert them into the filter housing. Position the power filter on the fish tank by hooking it to the side.

Adjust the aquarium water level until it reaches about an inch below the top edge. Switch on the power filter.

Frequently Asked Questions


Can you replace an aquarium filter cartridge?

Yes, you can replace the aquarium filter cartridge. You do not need a professional to change the filter. If you installed the filters by yourself, replacements should be straightforward.

Signs to know if fish tank filter cartridges need to be replaced?

Dirty or cloudy aquarium water indicates changing the carbon filter in the fish tank is long overdue. Other signs include reduced filtration flow rate and signs of the filter choking or breaking apart.

How often do you replace an aquarium filter cartridge?

Experts recommend changing the fish tank filter cartridge monthly, at least, though you don’t really need to replace it unless it’s falling apart. You can also change Tetra filter cartridges if you notice water flow reduction or water cloudiness.


How to install fish tank filter cartridge is as easy as 1-2-3. However, we cannot help but overemphasize the significance of reading the installation instructions for the filter type.

Although the steps look uncannily similar, some products require additional preliminary procedures. Be mindful of the filter’s location because it can be the difference between an optimally functioning fish tank filtration system and a poorly designed one.

The next steps are yours to take.