The filter is a crucial element for a fish tank’s success as they support maintaining water quality and fish health. Because there are numerous varieties of filters on the market, each with advantages and disadvantages, it can be difficult to choose the best filter, especially for new fishkeepers. There are many different types of filters available for fish tanks, each with different functionalities for different needs.
What To Consider When Buying A Fish Tank Filter
One of the most important factors to consider when buying a fish tank is the type of filter needed. The filter is essential in maintaining a healthy and clean environment for your fish to thrive in.
Size of Aquarium
The type and size of filter needed will depend greatly on the size of your aquarium. Filters with higher flow rates are required for larger aquariums in order to maintain proper water circulation and avoid debris accumulation. Smaller tanks may only need smaller filters with lower flow rates.
Type of Fish
Fish of various species require various levels of filtration. Fish that produce more waste than others need more powerful filtration systems. Additionally, some fish require particular filtration techniques, such as those that need a particular pH level or water flow rates. For example, betta fish require filters with low flow rates. It’s crucial to learn about the filtration needs of the fish you intend to keep in your tank.
Filtration Needs
Mechanical, biological, and chemical filtration processes are the three main categories to take into account when choosing a filter. Chemical filtration eliminates impurities like chlorine, biological filtration eliminates dangerous bacteria, and mechanical filtration removes debris from the water. You might require a filter that performs all three types of filtration or one that focuses on a single type, depending on your fish’s requirements.
Canister Filters
Canister filters are external filters, in a cylindrical or rectangular container. These filters are efficient and effective in removing impurities because they can purify a high volume of water, quickly.
Pros and Cons of Canister Filters
Pros:
- Highly efficient mechanical and biological filtration, great for fish with high bioloads.
- Versatile and can be used in aquariums of various sizes and types, including both freshwater and saltwater tanks.
- Easy to customize with different types of filter media to meet specific filtration needs.
- Easy to hide from view.
- Easy to maintain, as the filter media can be easily replaced or cleaned.
Cons:
- Expensive compared to other types of filters.
- Bulky and take up space below the aquarium.
- Difficult to install, requiring the use of hoses and fittings.
- Noisy if not properly maintained, as air bubbles can get trapped in the hoses and cause a humming sound.
- Require periodic maintenance to prevent clogging and ensure proper filtration, which can be time-consuming.
When to Choose a Canister Filter
Canister filters are ideal for those with large aquariums because they can handle a lot of water and effective filtration. Similarly, if your aquarium has a lot of fish in it, a canister filter can offer the filtration your aquatic animals need to stay healthy. If you have specialized filtration needs, canister filters can be made to order with various types of filter media to satisfy needs for specialized filtration. Finally, canister filters offer a gentle, constant water flow that doesn’t disturb delicate fish species.
Top-Rated Canister Filters
The Marineland Magniflow is a canister filter with an easily removable lid, a quick-release valve block that immediately stops water flow and separates from the motor housing.
- Easy to set up and maintain
- Effective filtration
- Expensive
The built-in motor in the lid of the AMOSIJOY 172GPH external canister filter allows for extremely quiet operation, producing only up to 30db of noise while achieving effective water filtration.
- Quiet
- Adjustable water flow
- Large in size
The Aqueon QuietFlow filter offers multiple water return options for optimal versatility: a spray bar, a water director and a water polishing unit.
- Water polishing unit
- Customizable filtration media
- Bulky
Hang-On-Back Filters
A hang-on-back filter, also known as a HOB filter, is a type of aquarium filter that hangs on the back of the tank, mounted using a bracket or clip.
Pros and Cons of Hang-On-Back Filters
Pros:
- Easy to install.
- Affordable.
- Compact.
- Easy to maintain.
- Provides mechanical, biological, and chemical filtration.
Cons:
- Limited aquarium size.
- Water flow can be too strong.
- Noisy, especially if not properly maintained.
- May require frequent cleaning.
- Visible in the aquarium.
When to Choose a Hang-On-Back Filter
Hang-on-back filters are generally best suited for small to medium-sized aquariums up to 75 gallons with a small number of fish or plants. They’re an excellent choice for beginners or those who prefer a simple, cost-effective, and easy-to-install filtration system.
Top-Rated Hang-On-Back Filters
The GRECH filter features 5W UV Sterilizer that helps eliminate algae and bacteria, keeping aquarium water crystal clear for 10 to 30 gallon tanks.
- Surface skimmer
- 5W sterilizer
- Large in size
The AMOSIJOY filter is completely sealed all around to prevent air leaks that could cause loud noises. This filter oxygenates the air with two water outlet functions: a duckbill outlet or a rain shower pipe.
- Affordable
- Quiet
- Bulky
The Cascade 300 Hang-On Filter quietly circulates water up to 300 gallons per hour (GPH). The Bio-Sponge cartridge optimizes the colonization of anaerobic bacteria.
- Bio-Falls system improves water oxygenation and helps with nitrate and ammonia removal
- Not flexible to varying water levels
Internal Filters
Internal filters fit inside the aquarium, completely submerged in the water and are frequently fastened to the glass with clips or suction cups.
Pros and Cons of Internal Filters
Pros:
- Easy to install.
- Cost-effective.
- Space-saving.
- Provides mechanical, biological, and chemical filtration.
Cons:
- Limited filtration capacity.
- May require frequent cleaning.
- Can be noisy.
- Water flow can be too strong.
When to Choose an Internal Filter
An internal filter is an excellent choice for beginner fishkeepers or those on a tight budget because they’re cost-effective. It can be easily installed and maintained, and offers mechanical, biological, and chemical filtration. Internal filters are also appropriate for aquariums with restricted space because of how little space they occupy.
Because internal filters might not offer enough filtration capacity, however, they might not be appropriate for larger aquariums or aquariums with high biological loads.
Top-Rated Internal Filters
The Hygger 4-in-1 filter purifies, filters, circulates, and pumps water. It features an adjustable flow rate of up to 210GPH.
- Two water outlet options
- Quiet
- Difficult to clean
The Aqueon Internal Filter is compact, fully submersible and allows for vertical or horizontal placement, which makes it easy to hide behind aquarium decor. This filter has a flow rate of up to 55 GPH.
- BioGrid that effectively removes ammonia and nitrites
- Can be placed anywhere in the tank
- Unattractive
This internal filter contains cartridge floss that catches debris and fish waste, while its ultra-activated carbon removes odors and discoloration.
- Affordable
- Adjustable to changing water levels
- No biological filtration
Sponge Filters
Sponge filters filter water mechanically and biologically using a porous sponge inserted into a tube or cylinder. Water flows through the sponge in a gentle flow, suitable for small or delicate fish. Normally, sponge filters are placed at the bottom of the aquarium or suction-mounted to the side of the tank.
Pros and Cons of Sponge Filters
Pros:
- Gentle water flow.
- Mechanical and biological filtration.
- Easy to maintain.
- Cost-effective.
- Safe for fry and shrimp.
Cons:
- Limited filtration capacity.
- Not suitable for high bioloads.
- May need frequent cleaning.
- Not aesthetically pleasing.
When to Choose a Sponge Filter
Sponge filters are a fantastic option for smaller aquariums (up to 30 gallons) with moderate bioloads, delicate fish species, and space constraints. They work well in aquariums for shrimp or fry.
Top-Rated Sponge Filters
The ALEGI Sponge Filter is your most simple, standard sponge filter that provides biological and mechanical filtration.
- Tubing included
- Check valve included, to prevent water and air backflow
- No setup instructions provided
While most sponge filters don’t offer multi-stage filtration, Hygger’s Double Sponge Filter contains sponge filtration as well as bio ceramic media balls so tiny creatures can grow quickly.
- Ceramic media balls included
- Easy to assemble
- No tubing included
The Pawfly Sponge Filters are the cheapest on the market, and smallest in size, fit for 5-10 gallon tanks. They offer excellent aeration and filtration at a low price.
- Tiny otion available
- Affordable
- Basic
Power Filters
A power filter hangs off the tank’s bank, where they draw water up a tube and into the filter. A waterfall-style overflow or a spray bar then returns the filtered water to the tank.
Pros and Cons of Power Filters
Pros:
- Effective filtration.
- Customizable, with the ability to add additional filter media or adjust the water flow rate.
- Easy to use.
- Versatile, available in a variety of sizes and flow rates.
- Affordable.
Cons:
- Noisy.
- Take up space: require space behind the aquarium to hang the filter.
- Limited filtration capacity: may not be suitable for very large aquariums or aquariums with high bioloads.
- Require regular maintenance.
When to Choose the Power Filter
Power filters are a good option for small to medium-sized tanks because they’re best suited for aquariums up to 75 gallons. Due to their simplicity of use and upkeep, power filters are a great option for beginners.
Top-Rated Power Filters
The Penguin Power Filter features a bio-wheel that offers superior wet/dry biological filtration to nitrify bacteria and quickly remove toxic ammonia and nitrate.
- Easy to clean
- High GPH
- More expensive than other options
The Tetra Whisper is one of the quietest power filters on the market with a SoundShield that provides a barrier between the motor and filter to minimize noise.
- Quiet
- Easy to assemble
- Complementary filter media can cause clogs
The Aqueon QuietFlow features an LED filter cartridge change indicator light that flashes when debris clogs the cartridge, with a self-priming internal pump.
- Quiet
- Easy setup
- Can be too powerful
What Is the Best Type of Filter for a Fish Tank?
The best type of filter for a fish tank is a canister filter. It’s highly effective in filtration in both saltwater and freshwater, large and small tanks, and tanks with high and low bioload. If you’re willing to deal with the initial cost and setup of the canister filter, you’ll be set up for success.
How Often Should You Change the Filter in a Fish Tank?
You should clean your fish tank filter every 2-4 weeks, depending on the size of your aquarium, the type of filter you have, and the number of fish and other inhabitants in your tank. Your aquarium water will stay clean and healthy for your fish and other aquatic pets if your filter is regularly cleaned and maintained.
How Do You Clean a Fish Tank Filter?
- Turn the filter off and unplug it from the power source before cleaning it.
- Remove the filter media, including the mechanical, chemical, and biological media by opening the filter.
- Rinse the media in a bucket of aquarium water.
- Clean the filter housing using a soft brush or sponge to get rid of any dirt or debris that may have accumulated.
- Once the filter housing and media have been cleaned, reassemble the filter and place the media in the proper compartments.
- Fill the filter with aquarium water to completely fill the filter.
- Reconnect the filter’s power cord and turn it on.
- Check the water flow and adjust it as necessary.
👉 Check out our full guide to find out how often to clean your filter and detailed instructions.
Tips For Maintaining Your Fish Tank Filter
- Clean your filter frequently to keep it working properly.
- To ensure optimal filtration, change the mechanical, chemical, and biological media occassionally because it may lose efficiency due to clogging with debris over time.
- Check the water flow from your filter frequently to make sure it is not too strong or too weak. The flow rate needs to be sufficient to keep the water moving without disturbing the fish or other aquatic animals housed in the tank.
- Keep the filter moist: If the filter needs to be cleaned, make sure to keep the filter media and housing moist to prevent killing the helpful bacteria that aid in waste breakdown and water quality maintenance.
- Check for leaks: To make sure that water is not leaking from the filter or returning into the tank, frequently look for leaks in the tubing or filter.
How To Troubleshoot Common Fish Tank Filter Issues
Noisy Filters:
- Check the water level: If the tank’s water level is too low, the filter may start to make noise. Verify that there’s enough water in the tank to cover the filter intake.
- Clean the impeller: The impeller can become clogged with dirt and debris and start to make noise.
- Check for air bubbles: make sure the filter is properly sealed and check the tubing for any air leaks.
Leaking Filters:
- Verify for any damage or cracks in the filter housing and replace if there is any damage.
- Examine the O-rings: over time, the O-rings in the filter can wear out and start to leak. If necessary, swap out the O-rings.
- Examine the tubing: make sure the tubing is connected and tightened correctly. Leaks can result from loose connections.
Filters Not Working:
- Verify the power source to make sure the outlet is functional and that the filter is plugged in correctly. To see if the filter works, try plugging it into a different outlet.
- Check the impeller: A dirty or clogged impeller can prevent the filter from functioning. To clean the impeller and get rid of any dirt, remove it.
- Inspect the filter for air bubbles because they can prevent it from functioning. Make sure the filter is properly sealed and check the tubing for any air leaks.
Which Filter is Best For You?
The best filter for your aquarium should have the features that suit the fish, aquarium size, and filtration needs, and your own preference. To guarantee the filter’s durability and effectiveness, proper maintenance is essential. Your fish tank can become a thriving aquatic ecosystem with the right filter and regular upkeep.