Filters

The filter is one of the most important pieces of equipment in any aquarium. It pulls in dirty water, passes it through filter media, and sends it back clean for your fish. More than that, it’s home to beneficial bacteria that keep your water safe and stable, making it a key part of a healthy tank. There are plenty of options to choose from—hang-on-back filters, canister filters you can hide in a cabinet, and more—so it’s worth picking one that suits both your setup and your fish. As a general rule, bigger is better: it’s always safer to over-filter than under-filter your aquarium. To keep things running smoothly, swap out or rinse parts of the filter media a few times a year, but be careful not to wash away all the good bacteria your tank depends on.