“REEF-SPEC" 500g Water-Polishing Activated Carbon Filter Media (comes with Filter Bag for Instant Application)
“REEF-SPEC" 500g Water-Polishing Activated Carbon Filter Media (comes with Filter Bag for Instant Application)
“REEF-SPEC" 500g Water-Polishing Activated Carbon Filter Media (comes with Filter Bag for Instant Application)

“REEF-SPEC" 500g Water-Polishing Activated Carbon Filter Media (comes with Filter Bag for Instant Application)

Brand: Red Sea
Item Number: RDSE-ACTCRB500G

Regular price $19.99 On Sale

Only 31 left in stock!

Estimated Arrival: Between Jun 16 and Jun 22. *ETA for USA only. For accurate lead times, call us at 727-214-7750

Large, Custom, Or Backorder: Arrival Times May Vary.

Shipping Policy: Little or No Shipping Charges for Regular-Sized Items; We Cover Part of the Freight Costs for Large Items Shipped Nationally. See Shipping Policy.


  • Extremely affordable and efficient way of polishing water - just add flow
  • Removes yellow and blue tint to aquarium water, dramatically increasing visual appeal and PAR impact of aquarium lighting
    • Studies have shown unpolished, yellowed aquarium water reduces lighting effectiveness and PAR by 15-25%
  • Absorbs excess medications from previous disease treatment
  • Varied Pore Size Structure effectively traps a wide variety of aquarium pollutant molecules
  • Peak Absorption Capacity maximizes longevity of useful life, making carbon changeouts less frequent

Two Tides Advisory:

Activated carbon has been used for decades in water treatment and purification as a natural way to filter out very fine molecular particles that tint and slightly cloud water to hinder light penetration, as well as negatively affect chemical balance. In an aquarium setting, carbon is also extremely useful to remove excess medications after treating for a potential or apparent aquatic illness.

REEF SPEC Activated Carbon is a very solid upper middle ground option for those that want the instant clearing and polishing effects of higher end carbon, while still at a manageable price point for most hobbyists. We see it as a good gateway into upper echelon builds to experiment with the difference between budget and premium chemical filtration.

We advise using this media with a Carbon / Media Reactor if space and budget allows. This will ensure that water will be forced into every pore of the media, which will allow the entire useable surface area of a square football field per teaspoon of media to be utilized. Not only will this help us get the most bang for our buck in terms of the largest amount of chemicals being filtered out for the given amount of carbon, but will also give us a slight edge in longevity, as chemicals forcefully flow through the entire pore structure, not just stopping at the outer edges due to improper flow, and our carbon will effectively filter for longer.

If this carbon is used in a Filter Bag, it's no big deal. Simply fill the bag 60-80% full of carbon, tie it off, and place in a high flow area of your filtration system. Just keep in mind that most likely the entire surface area of the carbon will not be used, but this isn't so bad as it is relatively affordable to replace anyways.

Available Sizes:

  • 250g
  • 500g
  • 1000g

Areas Tested and Optimized for Activated Carbon Quality:

  • Product Density
  • Total Surface Area
  • Pore Volume
  • Mesh Size
  • Iodine Number
  • Methylene Blue Number
  • Ash Level
  • Leachable Phosphate 

Size and Shape: 0.6-2.3mm flakes

Density: 0.48g/mL

Pore Volume (PV): 1.04 g/mL

Total Surface Area (TSA): 1000m²/g

TSA/PV: 990 m²/mL

Small Organic Molecule Absorption: 1000 mg/g

Large Organic Molecule Absorption: 280 mg/g

pH in Distilled Water: >8

Phosphate Output (“Phosphate Leeching”): 0.000001 g/mL

What's Included:

  • (1) REEF SPEC 500mL Activated Carbon Package
  • (1) Carbon Filter Bag for instant application into system

In this video, CTO of Red Sea - Neil - gives us a detailed overview of their REEF SPEC Activated Carbon. Thanks Neil!

 Below, we’ve included the REEF SPEC Activated Carbon Manual, which shows us how to use this specific carbon media for the following uses

  • Organic Load and Yellow Tint Removal
  • Post-Medication Treatment Absorption
  • Ozone Post-Treatment
  • Use with Filter Media Bag
  • Use with Carbon Reactor / Canister Filter

REEF SPEC Activated Carbon Usage Manual

Have any further questions that aren't answered here? We'd love to hear from you, and learn how we can help you be as successful as possible in this wonderful hobby.

You can call in to 727-214-7750 to speak with Tyler from our team to determine how to create your Ideal Aquarium Build.

Also feel free to reach out to us at info@twotidesaquariumsupply.com and we will aim to respond back within the next few hours.


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