Best canister filter for a 75 gallon tank
The best canister filter for a 75-gallon tank should provide reliable biological filtration, enough media space for the tank’s bioload, and…
Buying guides
Help matching aquarium filters and pumps to tank size, bioload and noise tolerance.
Best For Tank
Best canister for a planted 40 breeder
The best canister for a planted 40 breeder balances gentle, consistent circulation with enough mechanical and biological media for the…
Best filter for a 20 gallon community tank
For most 20-gallon community aquariums, a quiet hang-on-back filter or air-driven sponge filter is the best starting point. The right…
Best Filter for a Heavily Stocked Goldfish Aquarium
Heavily stocked goldfish aquariums need more than a filter rated for the tank’s gallon capacity. Look for strong mechanical filtration,…
Best filter if you already have an air pump running
If you already have an air pump, a sponge filter is usually the simplest match. Learn when to choose one, how to size it, and when an…
Best hang-on-back filter for a goldfish tank
The best hang-on-back filter for a goldfish tank is one with more capacity than the tank-size label suggests, adjustable flow, a protected…
Best quiet filter for a bedroom aquarium
The quietest bedroom aquarium filter is usually one with adjustable flow, a fully submerged or well-isolated motor, and enough capacity to…
Best sponge filter for a fry tank
The best sponge filter for a fry tank provides gentle flow, dependable biological filtration, and no exposed intake that can trap small…
Media
Filter floss as cheap mechanical media
Aquarium filter floss is an inexpensive way to trap fine particles and improve water clarity. Learn which type to buy, how to use it…
Polishing pad when water will not clear
A polishing pad can clear fine particles, but it cannot fix every type of cloudy water. Check the pad, water flow, filter setup, and the…
Replacement ceramic rings for a canister
Replacement ceramic rings can restore the biological media capacity of a canister filter, but the right choice depends on basket space,…
Canister Filter Media Stack Order
The usual canister filter media order is coarse mechanical media first, followed by finer mechanical media, chemical media if needed, and…
Cartridge lock-in cost after year one
Aquarium filter cartridges can look inexpensive at first, but replacement schedules, multiple cartridges, shipping, and compatibility can…
Prefilter sponge on a HOB intake
A prefilter sponge on a HOB intake protects fry and shrimp, catches debris before it reaches the impeller, and adds biological filtration.…
Yearly Cost of Replacement Cartridges Versus Reusable Media
Replacement cartridges are convenient, but reusable sponge and biological media can lower ongoing aquarium filter costs. Here is how to…
Live plants reducing the need for chemical media
Healthy, actively growing aquarium plants can take up some dissolved nutrients and reduce the need for chemical media used routinely. They…
When water changes beat buying chemical media
Chemical media can target specific substances, but it cannot replace routine maintenance. For many common water-quality problems, a…
Price & Buying
Canister filter for a 40 gallon planted tank
A 40-gallon planted tank usually benefits from a quiet canister filter with adjustable or controllable flow, enough media capacity for the…
Internal power filter for a 5 gallon tank
A small internal power filter can provide mechanical and biological filtration in a 5 gallon aquarium, but the right choice depends on…
Quiet air pump for a bedroom sponge filter
A quiet air pump for a bedroom should provide enough airflow for the sponge filter without excessive vibration or a constant hum. Focus on…
Quiet HOB filter for a 10 gallon bedroom tank
The quietest HOB filter for a 10-gallon bedroom tank is usually one with adjustable flow, a properly sized intake, flexible media options,…
Cost of a Canister Versus Two HOBs on a 75 Gallon
On a 75-gallon aquarium, two HOB filters may cost less to buy and maintain, while a canister can offer cleaner appearance, more media…
How much does an aquarium filter cost
Aquarium filter prices vary widely by filter type, tank size, flow capacity, and included media. Here is how to compare the upfront price…
Is a Cheap Hang-on-Back Filter Enough for a 10 Gallon?
For many lightly to moderately stocked 10-gallon aquariums, an inexpensive hang-on-back filter is sufficient. The important factors are…
Troubleshooting
Use Cases
Best air pump for a multi-tank rack
The best air pump for a multi-tank rack is sized for the total number of air outlets—not just the largest aquarium. Learn how to match pump…
Best Battery Backup Air Pump for a Power Outage
A battery backup air pump can keep oxygen moving when your aquarium’s main filter stops during a power outage. Here’s how to choose one…
Filter for a 2.5 gallon nano
A 2.5-gallon aquarium needs compact filtration with gentle, adjustable flow. Learn which filter types fit nano tanks and how to avoid…
Sponge filter and air pump kit for a quarantine tank
A sponge filter and air pump kit is a simple, medication-friendly choice for quarantine tanks. Match the filter to the tank’s volume and…
UV sterilizer as an add-on to a canister loop
A UV sterilizer can be added to many aquarium canister-filter systems, but placement and flow rate determine whether it performs as…
Air pump that survived a week-long vacation outage plan
A battery backup air pump can help keep aquarium water moving during an outage, but a week of protection takes verified runtime, a tested…
Filter for a betta tank
A good betta filter keeps water moving through biological media while maintaining a gentle current. Choose by tank size, adjustable flow,…
Filter for a planted tank
A good filter for a planted tank provides dependable biological filtration and circulation without blasting plants or stressing fish.…
Filter for a turtle tank
Turtles produce more waste than similarly sized fish, so choose a filter with ample biological and mechanical capacity—not just one whose…
Filter for a paludarium
The right paludarium filter depends on the size and stocking of its aquatic section. Compare sponge, internal, hang-on-back, and canister…
Reviews
How to read aquarium filter reviews
Star ratings alone won’t tell you whether an aquarium filter suits your tank. Check the reviewer’s setup, the exact filter version, and how…
Warranty on a Canister That Was Never Primed Correctly
Running a canister filter without priming it correctly can damage parts, but it does not automatically settle whether a warranty applies.…