Fluval C2 Activated Carbon 3-Pack

Fluval C2 Activated Carbon is the chemical filtration refill for the Fluval C2 Power Filter. Each box holds 3 carbon inserts shaped for the C2’s media stage, so there’s no cutting or bagging.

What it does

Activated carbon adsorbs dissolved compounds that cause odor and yellow or tea-colored water. Fluval also notes it removes heavy metals. The result is clearer, better-smelling water in freshwater and saltwater tanks.

How to swap it

• Unplug the filter and lift out the old carbon insert.
• Rinse the new insert briefly to clear dust.
• Seat it in the chemical stage and restart the filter.

How often

Carbon gets used up. Most keepers replace it about once a month. With 3 inserts per box, one pack covers roughly a season of steady use.

When to leave it out

Remove the carbon while you dose fish medications, since it will pull the medication out of the water. Put a fresh insert back after the treatment ends to clean up what remains.

Do you need carbon?

Many tanks run fine without it if water changes are regular. Carbon earns its place when driftwood tints the water, after medication, or when an odor won’t go away. It does not remove ammonia or nitrate.

Write the date on the box or a strip of tape on the filter when you swap an insert. Carbon gives no visible sign that it is spent, so a simple calendar reminder is the easiest way to keep it working. Store unopened inserts sealed and dry so they don’t pick up odors from the room.

Other options

If you’d rather fill your own bags, Fluval carbon in media bags is the loose version. For organics without carbon, Seachem Purigen can be recharged.