Performs mechanical filtrationCaptures large particlesCustom fit to prevent bypassEnhances biological filtrationFor freshwater and marine aquariumsFor use with Fluval FX5 External Canister Filter, sold separately
The store doesn't carry the 500 series filter supplies, so I had been forced to go elsewhere. I wish someone had told me they were available online. I'd much rather shop @ Petco!These fit exactly into the FX5 series filters. You can cut up foam but this is much easier. It costs a little more, but the convenience is worth it. Just remember, you need to order 2 boxes, as there are 4 filters in the Fluval 500 series.