The Best Aquarium Filters

Buying Guide for Aquarium Filters

Why buy an aquarium filter?

Since tanks are dense and enclosed, it’s easy for the water inside to become polluted, especially if it doesn’t cycle. Filters constantly work to clean the water in the aquarium of debris, toxic substances, and biowastes like nitrates and ammonia. They also aerate the tank’s water so that your fish can breathe better. They save you the time and effort of having to manually scoop out your fish and clean the tank once a week.

What should you consider in an aquarium filter? 

• Tank Size: It’s important to know how large your tank is before picking a filter for it. Specifically, you’ll want to know how many gallons of water your tank is designed to hold. If you don’t know the exact amount, you should at least have a good idea of the size range it falls into. Any filter you buy will list the tank size it should be used in (5-gallon, 10-to-20 gallon, etc.).
• Type: The main types of aquarium filters you’ll find are sponge, internal (submersible), undergravel, HOB, canister, and sump (wet/dry) filters. Sponge filters are inexpensive and easy to use, but they also require weekly water changes and maintenance to prevent clogging. Internal filters go in the water and are generally compact and efficient. Under gravel filters are plastic mesh screens on the bottom of the tank, largely hidden from view. HOB filters are more complex, but they provide high-level filtration. Canister filters are powerful, effective, and customizable, though they’re more expensive and high maintenance. Sump filters are low maintenance and quiet, but they’re also bulky, may require special modifications to install, and often need to be paired with another type of filter.
• Filtration Type: There are three main filter types: mechanical, chemical, and biological. Mechanical filters automatically collect and remove debris through fine mesh or cotton filter pads. Chemical filters use filter media, resin chips, activated carbon in a bag, cartridge, or basket inside the filtration system, which attracts and soak up toxins from the water. Biological filters take ammonia and nitrites in the water and convert them to a nontoxic form to help prevent your fish from getting sick. Depending on the type of filter, it may use only one of these stages to clean your aquarium water, while others use a combo or two or all three.

Which type of filter is best for each type of tank?

For small aquariums (10-gallon or less), you’ll probably want a sponge, under gravel, or internal filter. Internal filters are especially good for beta fish, shrimp, and plants in small tanks. You’ll want to avoid an under gravel filter if you have a lot of bottom-feeder species, as they may get stuck underneath them. HOB filters will work in just about any type of aquarium, as long as you find one that’s the proper size for your tank. Canisters are best suited to larger tanks (at least 20 gallons in size, though ideally 50 gallons or more) and aquariums with a high number of fish. Sump filters are ideal for marine and reef tanks of aquariums that have been professionally aquascaped.

Our Picks for the Best Aquarium Filters

Pros: The Marineland Penguin Bio-Wheel Power Filter removes waste, discoloration, and odors through mechanical and chemical processes. It comes with a rotating bio-wheel that filtrates out all waste in your tank. Plus, there are multiple levels to the filtration system for an even better clean. It also comes in several sizes and is designed to be compatible with almost any tank.

Cons: It may be a little noisy.

Bottom Line: Keep your fish happy and your aquarium clean with this filter. It’s an all-around solid option that’s designed for efficient cleaning.

 

Pros: The AquaClear Fish Tank Filter keeps your operating costs low while still doing a great job at cleaning up your tank. The installation process is straightforward and can be done in no time. There are multiple layers of cleaning power: mechanical, chemical, and biological. Plus, it filters up to seven times more water than similar fish tank filters.

Cons: Occasionally, the impeller needs a little help getting going after cleaning the filter.

Bottom Line: This filter will get your tank clean without costing you lots of energy.

 

Pros: The Penn-Plax Cascade Canister Filter for Large Aquariums is a classic, inexpensive, yet effective option. It’s meant for major tanks, between 30 and 200 gallons. Thanks to the power it has, it can clean up to 115 gallons per hour, leaving your tank looking clear and healthy. This filter works great for both freshwater and saltwater tanks. As an added perk, there’s a primer button that you can press to get it ready to clean.

Cons: It isn’t quiet.

Bottom Line: Clean up your large tank with this effective filter that will keep your water fresh for your aquatic friends.

 

Pros: The Tetra Whisper EX Silent Multi-Stage Power Filter is made specifically to be extra quiet. It’s a multistage filtration system that results in clear, clean water fast for your aquarium. The design keeps water flowing continuously to avoid having to worry about debris build-up. This filter is meant to be convenient and straightforward: just set it up and let it go to work.

Cons: This filter works best if your aquarium has a relatively high-water level.

Bottom Line: This filter is great if you’re looking for an option that’s easy to install and that works quietly but well. Just set it up and let it do its job for aquariums up to 75 gallons.

 

Pros: The Penn-Plax Cascade Hang-on Aquarium Filter is a smaller filter that can be easily mounted on your aquarium for effective cleaning. It works quickly, pushing 100 gallons of water per hour through the filter. This filter works well with both freshwater and saltwater aquariums. Even an adjustable flow knob lets you either increase or decrease the water flow. The filter has two-sided cartridges that remove chemicals and toxins to keep the tank clean and your fish feeling healthy!

Cons: Because of its smaller size, it might not be as powerful.

Bottom Line: This filter quietly and effectively cleans aquariums. You can fix this filter up to make it work exactly how you want it with a bit of customization.

Final Thoughts

There are quite a few different filters out there that provide helpful features and may be more efficient for your specific tank. If you’re looking for a new filter for your current fish tank or are planning to buy some new aquatic pets, consider these options to find one that will give your fish a clean home.