Do these cartridges include activated carbon?

No, these standard Rite-Size C cartridges have a white mechanical floss pad and a bio-wheel, but no carbon. For chemical filtration, you would need to add a separate carbon pack or choose the carbon version.

How often should I replace the cartridge?

Marineland recommends replacing every 4 weeks, but many owners extend to 6-8 weeks if the cartridge isn't clogged. Rinse the cartridge in tank water between changes to remove debris and avoid killing bacteria.

Will this cartridge fit my Marineland Emperor filter?

No, the Penguin cartridges are designed only for Penguin series filters. Emperor models use a different size and shape. Always verify your filter model and cartridge size (A, B, or C).

Can I use these without the bio-wheel?

The cartridge comes with the bio-wheel attached. You could remove the wheel, but it’s intended to spin for biological filtration. Skipping it may reduce bacteria colonization. Many users keep the wheel for its added aeration.

Marineland Penguin Bio Review (2026)

What it is The Marineland Penguin Bio-Wheel Replacement Filter Cartridges, Rite-Size C, are disposable filter packs designed specifically for Marineland Penguin power filters (models 150, 200, 350, and similar). Each cartridge combines a mechanical filter pad to trap debris with a built-in bio-wheel that rotates as water flows, promoting colonization of beneficial bacteria for biological filtration. The Rite-Size C is for mid- to large-sized aquariums (usually 75-100 gallons depending on flow rate). A 6-count pack provides several months of replacements. ## Key features to know – All-in-one design: The cartridge includes a floss pad for mechanical filtration and a bio-wheel that aerates and houses nitrifying bacteria. This simplifies maintenance, you replace the entire unit.

Self-priming bio-wheel: The rotating wheel stays moist even if the filter loses power, helping bacteria survive temporary outages. It also adds oxygen to the water.
Rite-Size C compatibility: Fits only Marineland Penguin filters that accept C cartridges (e.g., 150, 200, 350). Check your filter model before buying, using the wrong size causes leaks or poor performance.
Convenience: Pre-assembled and ready to use; just remove the old cartridge and snap in the new one. No cutting or customizing.
Moderate filtration media: The floss pad is relatively fine but not as dense as some competitors, so it may clog faster with heavy bioloads or messy fish. ## Who it is best for – Owners of Marineland Penguin power filters who want an easy, drop-in replacement without modifying media. Ideal for beginners or those who prefer minimal maintenance.
Aquarists with moderate stocking levels in community tanks with fish like tetras, barbs, or cichlids that produce average waste.
Busy hobbyists who change cartridges monthly: The simple swap saves time compared to cutting foam or layering media.
Tanks needing biological boost: The bio-wheel helps establish and maintain beneficial bacteria, especially in newer setups or after medication. ## Things to consider before buying – Compatibility only: This cartridge works exclusively with Marineland Penguin filters that use size C. It does not fit other brands or smaller Marineland models (e.g., Mini, Small). Double-check your filter’s manual or look at the current cartridge.
Cost per cartridge: Buying a multi-pack like 6-count reduces per-unit cost, but it’s still pricier than some homemade or reusable media. Long-term, you may save by using cut-to-fit foam and separate bio media.
Potential nitrate buildup: Disposable cartridges are often removed monthly, which can dump trapped debris into the water and spike nitrates. Some aquarists prefer rinsing the cartridge in tank water between changes to preserve bacteria.
Bio-wheel efficiency: The bio-wheel is effective but can become noisy if misaligned or if the bearing wears out over time. The cartridge replacement includes a new wheel, so this resets the wear.
Not customizable: If you want chemical filtration (carbon, phosphate remover), this cartridge does not include any. You would need to add a separate media bag or choose a different filter setup.
Limited for heavy bioloads: For messy fish (goldfish, large cichlids) or high-stocked tanks, the floss may clog quickly. You might need to pre-filter with a sponge to extend life. ## Alternatives to consider – Cut-to-fit foam and bulk bio-media: For those with Marineland Penguin filters, you can remove the cartridge entirely and use open-cell foam pads plus ceramic rings or bio-balls. This is more upfront work but cheaper long-term and offers better biological filtration.
Other replacement cartridges: Marineland also makes Rite-Size A and B for smaller filters, as well as versions with carbon. Consider if you need chemical filtration included.
Sponge pre-filters: Adding a sponge over the intake prevents large debris from hitting the cartridge, prolonging its life. This works with any cartridge system.
Upgrade to a different filter: If you dislike disposable cartridges, consider a filter with reusable media like the Fluval AquaClear or Seachem Tidal series, which allow full customization. ## Final thoughts The Marineland Penguin Bio-Wheel replacement cartridges are a reliable, easy-choice for keeping your Penguin filter running. They work well for standard community tanks, but cost and waste concerns may lead experienced aquarists to alternative media. Always check compatibility with your specific filter model before purchasing, and remember to rinse the cartridge in used tank water (never tap water) to preserve the beneficial bacteria. For the best value, consider buying in bulk or pairing with a pre-filter sponge.