Aquarium Filter Foam Insert Hagen Fluval Bio-Foam 2 for 30–40 gallon tanks

Hagen Fluval Bio-Foam 2 is a replacement filter foam insert designed for use in canister filters serving 30–40 gallon aquariums. The open-cell porous structure captures suspended particles while providing a large surface area for colonization by nitrifying bacteria. Suitable for freshwater and planted tanks, this foam functions as both a mechanical and biological media layer to support clearer water and a more stable aquarium environment.

Advantages

The foam combines mechanical particle trapping with a highly accessible surface for beneficial bacteria, reducing ammonia and nitrite through biological filtration. Its resilient construction retains shape during handling and rinsing, allowing repeated maintenance without rapid degradation. The neutral material does not affect water chemistry and fits standard media baskets in compatible Fluval canister filters for straightforward replacement.

Suitable for

• Replacement media layer in canister filters for 30–40 gallon (approx. 115–150 L) aquariums
• Mechanical pre-filter to trap debris in freshwater and planted tanks
• Support surface for biological filtration and beneficial bacteria colonization
• Use in internal filters or custom media setups where an open-cell foam pad is appropriate

Key specifications

• Material: open-cell porous filtration foam
• Filtration functions: mechanical and biological
• Compatibility: sized for use in canister filter media baskets for 30–40 gallon aquariums
• Maintenance: washable and reusable with careful rinsing

How to use

Remove the existing foam media from the filter housing and inspect the media basket for debris. Rinse the new foam gently in dechlorinated water or tank water to remove loose particles before installation. Place the foam into the designated media slot, ensuring it sits flat and allows water flow through the pad. Reassemble the filter according to the manufacturer’s instructions and prime as required. During routine maintenance, remove the foam and rinse it gently until the outflow clears; avoid vigorous squeezing that can dislodge beneficial bacteria.

Usage recommendations

Rinse foam media using aquarium water during scheduled water changes to preserve bacterial colonies; replace when structural breakdown or irreparable clogging reduces flow or filtration effectiveness.