Fish Tank Filter Sponge, Pads & Foams

Replacing your filter sponge regularly keeps water clean and your fish healthy, but it's best practice to never change all the media at once, rinsing old sponges in tank water rather than tap water helps preserve the beneficial bacteria that break down harmful ammonia and nitrite, so your filter keeps working biologically as well as mechanically. When choosing a replacement, match the pad's density and pore size to your filter model and stocking level, finer pads trap more debris and need more frequent rinsing, while coarser foam suits heavily planted or lightly stocked tanks and needs less upkeep. If you're unsure what size or type of media your setup actually needs, our Best Fish Tank Filters: A Practical Buying Guide can help you work it out before you buy.