Fluval AC50 BioFoam Filter Insert

The Fluval AquaClear BioFoam is the replacement mechanical foam insert for the AquaClear 50 (AC50) power filter. Water flows through the foam first, trapping debris and waste while the porous surface grows the beneficial bacteria that keep your aquarium cycled. Fresh foam means strong, even flow and clear, healthy water. Formerly sold as AquaClear Foam.

Restock the whole AC50 media stack together: Activated Carbon for chemical filtration and Ammonia Remover for freshwater ammonia control. Browse everything in our Filter Media & Cartridges collection.

Features

• Mechanical foam traps waste, debris, and free-floating particles before they cloud the water
• Large porous surface hosts beneficial bacteria for continuous biological filtration
• Maintains strong, even flow through the filter between cleanings
• Custom-cut to fit the AquaClear 50 / Fluval AC50 media basket, no trimming needed
• Reusable: rinse and reinstall several times before replacing
• Safe for both freshwater and saltwater aquariums

How to Use

Rinse the new foam in dechlorinated or used aquarium water, then set it at the bottom of the AquaClear media basket so water passes through it first. At each cleaning, rinse it in siphoned tank water rather than tap water, which would kill the bacteria colony. Replace the foam roughly every two to three months, or once it no longer springs back into shape.

Specifications

Recommended Pairings

• AquaClear / Fluval AC50 power filter, the filter this foam fits
• AquaClear AC50 Activated Carbon for chemical filtration and odor control
• AquaClear AC50 Ammonia Remover for extra ammonia protection in freshwater
• Filter Media & Cartridges, all replacement media in one place

FAQ

Which filter does this fit? The AquaClear 50 (also sold as the Fluval AC50), the model rated for 20 to 50 gallon aquariums. Other AquaClear sizes use their own foam.

How often should I replace it? Rinse it at every cleaning and replace it every two to three months, or when it stays compressed. Stagger foam and biomedia changes so you never swap all media at once.

Can I use it in a saltwater tank? Yes. The foam is inert and works the same in freshwater, brackish, and marine setups.

Single or 3-pack? The foam is identical; the 3-pack simply keeps spares on hand so you always have fresh media ready.