Best HOB Filters
What to look for in a hang-on-back filter: when it suits a tank, flow and size, media and cartridges, intake safety, noise and restarts.
Guides & advice
Aquarium Guides
Best Nano Aquarium Filters
Choosing a nano aquarium filter: sponge, hang-on-back, internal and small canister options, gentle flow and intake safety, and easy maintenance.
Best Aquarium Heaters
An aquarium heater has one job that matters more than every feature on the box: keep the water within a stable, appropriate temperature range for the animals you keep.
Best Aquarium Lights
The best aquarium light depends on what the aquarium contains.
Best Air Pumps
The best aquarium air pump is not automatically the largest or most powerful model.
Best Aquarium Thermometers
An aquarium thermometer is a small piece of equipment with an important job: independently verify the water temperature.
Best Gravel Vacuums
Choosing a gravel vacuum: tube and hose size, manual and self-priming designs, use on gravel, sand and planted substrates, and flow control.
Best Aquarium Test Kits
An aquarium test kit turns invisible water conditions into information you can act on.
Cleaning a Sponge Filter
When and how to clean a sponge filter and its airlift tube without destroying the beneficial bacteria, then restart it and check the flow.
Cleaning a Canister Filter
Clean a canister filter safely: rinse the media without losing the biofilter, clean the impeller and hoses, reprime it, and check it afterwards.
Replacing Filter Media
Filter media does not need to look clean to be useful. In an established freshwater aquarium, sponges, ceramic media, and other filter surfaces hold much of the biofilm that helps process fish waste.
Heater Maintenance
Aquarium heater maintenance: monthly checks, removing buildup, testing accuracy, safe placement, signs of failure, and when to replace it.