Cartridges: What Is Consumable and What Is Not

Some filters are designed around replaceable cartridges. Knowing which parts are consumable saves both money and a crashed cycle.

The cartridge is mostly mechanical

Most drop-in cartridges are floss wrapped around carbon. Replacing one throws away the trapped debris and the spent carbon — and also some of your bacteria.

Keep some maturity

Where a filter takes two cartridges, stagger the replacements. Where it takes one, add a small sponge alongside so something mature always stays in the box.

Buy for the model, not the shape

Cartridges are model-specific. We list which unit each pack fits rather than leaving you to compare photographs.