Tetra Whisper Bio-Bag Medium Filter Cartridges — 12-Count Pack, Activated Carbon & Mechanical Filtration

When you want a straightforward, economical way to maintain clean aquarium water, these medium Bio-Bag cartridges slip into Whisper and compatible Tetra filters for mechanical and chemical filtration. Sold as a 12-count multi-pack of unassembled bags plus aerobic frames, they are made to fit specific Tetra Whisper and TetraTec filter models and give you a month-long lifespan under normal conditions. The bags pair a dense dual-sided mesh for trapping particles with activated carbon to reduce discoloration and scent.

Which filters do these medium Bio-Bags fit?

These medium cartridges are sized for many Whisper and Tetra internal and power filters. They are color-coded to help you match the right cartridge to your filter model and are compatible with a range of medium-sized units commonly used in home aquariums.

• Compatible models include PF10 Power Filter, 10i and Reptofilter 90 GPH internals, and medium Whisper power filters.
• Also fits certain TetraTec 300/500 and larger Whisper internal frames when specified.
• Check your filter color code and model number before purchase to ensure a correct fit.

How do I assemble and install a Bio-Bag cartridge?

The Bio-Bag multi-pack ships unassembled to save space. Assembly is quick and requires no tools: slide the bag over the aerobic frame, add the carbon packet, fold the flaps and secure the clip. Rinse to remove dust and then insert it into the filter slots as directed by your filter manual.

• Detach the clip from the aerobic frame, slide the bag over the frame, and add the activated carbon pouch.
• Fold the frame flaps down, snap the clip into place, and rinse under cool tap water to remove carbon dust.
• Place the finished Bio-Bag into the filter housing and replace monthly or sooner if visibly dirty.

What filtration benefits can I expect from these cartridges?

Each Bio-Bag combines mechanical and chemical filtration: the dual-sided mesh traps waste and particulate matter while the activated carbon adsorbs dissolved organics that cause color and odor. They simplify maintenance and help keep aquarium glass and decor looking clearer between water changes.

• Mechanical: dense mesh captures uneaten food, fish waste and suspended debris.
• Chemical: activated carbon reduces discoloration, tannins and mild odors.
• Maintenance: designed for monthly replacement to maintain performance and flow.

When should I replace or change a Bio-Bag?

Under normal aquarium conditions, replace the cartridge approximately every 30 days. Replace sooner if water flow decreases, the bag becomes visibly clogged, or the tank develops persistent discoloration or odor.

• Monthly replacement is recommended for consistent performance.
• If you notice reduced flow, replace immediately to protect filter pump health.
• In heavily stocked tanks or after medication treatments, change more frequently.

Who is this for: The Tetra Whisper Bio-Bag Medium 12-pack is aimed at home aquarists who use Tetra Whisper or compatible filters and want an affordable, ready-to-install supply of replacement cartridges. It's a practical choice for beginners seeking simple upkeep, hobbyists who prefer scheduled maintenance supplies, and anyone running medium-sized home aquariums that benefit from combined mechanical and carbon filtration.