Fluval AC20/30 Active Carbon Insert

The Fluval AquaClear Activated Carbon Insert is premium activated carbon that keeps the water in your AquaClear 20 or AquaClear 30 hang-on-back filter clean and crystal clear. Its highly porous surface adsorbs odors, discoloration, tannins, and dissolved organic waste, so your tank looks its best and your fish stay healthy. It is also the go-to media for pulling leftover medication out of the water after a treatment.

Restocking media or dialing in a new setup? Browse all filter media and cartridges at Squeaky's Aquatics.

Why Activated Carbon

• Removes odors and toxins. Adsorbs the dissolved organics, odors, and discoloration that cloud your water and dull your tank.
• Improves water clarity. Clears yellowing from driftwood tannins and leaves the water bright and polished.
• Clears out medication. Run it after a treatment to strip leftover medication from the water column before it stresses your fish.
• Freshwater and saltwater safe. Works in tropical, coldwater, and marine aquariums alike.

How to Use

• Fits the Fluval AquaClear 20 (AC20, Mini) and AquaClear 30 (AC30) power filters. One insert covers both models.
• Place it in the media basket after the BioFoam. Rinse away loose dust under tank water before the first use.
• Replace roughly every 3 to 4 weeks. Carbon becomes exhausted with use, so this is a replace-when-spent media, not a rinse-and-reuse one.
• Remove carbon while dosing medications, then add fresh carbon afterward to clear the water.

Specifications

Recommended Pairings

• Fluval AquaClear Power Filter, the hang-on-back filter this insert is built for.
• Need mechanical and biological media too? Add the AquaClear BioFoam and BioMax.
• Want carbon plus phosphate or ammonia control? Try the Clear-Carb or Zeo-Carb.
• Running a larger filter? Grab the AC50 or AC70/110 Activated Carbon instead.

Frequently Asked Questions

How often should I replace the carbon?
Every 3 to 4 weeks. Once carbon is saturated it stops adsorbing and can slowly release what it captured, so replace it rather than rinsing and reusing.

Does carbon remove ammonia or nitrate?
Not effectively. Carbon targets odors, discoloration, and dissolved organics. For ammonia use the Ammonia Remover or Zeo-Carb, and for lasting control build your biological filter with BioMax.

Should I run carbon all the time?
It is optional. Many keepers run it continuously for clear water, while others use it as needed to clear tannins or remove medication. Just remove it before dosing meds.

Is it reef safe?
Yes. Activated carbon is safe and widely used in marine and reef aquariums for water polishing.