Red Sea

RED SEA - REEF-SPEC™ Carbon 2000ml

Red Sea 's Reef Spec is a super-activated carbon for marine and reef aquariums . Thanks to its unique technical characteristics, REEF-SPEC™ carbon is the best choice for marine and reef aquariums.

Learn more

The size of the granules and their micro and macroporous structure allow very high total absorption and rapid extraction of organic pollutants. REEF-SPEC CoalHas an extremely low phosphate rejection rate and minimal ash content. It has no influence on the pH of the aquarium water.

REEF-SPEC CoalOf Red Sea needs replacing less frequently than lesser quality carbons. It is an effective and affordable solution to obtain the best water quality in marine and reef aquariums.

Main characteristics :

  • Rapid extraction of organic pollutants
  • Very high total absorption capacity
  • Ultra low phosphate releases
  • Ultra low ash
  • Usable in freshwater and saltwater
  • Filtration bags included (250g, 500g, 1000g)

Watch the Charcoal presentation video Red Sea REEF-SPEC™

REEF-SPEC™ Carbon Specification Table

Form Flakes of 0.6 – 2.3 mm
Density 0.48g/ml
Pore volume (PV) 1.04ml/g
Total Area (TSA) 1000m2/g
ASD/PV 990m2/ml
Adsorption of small organic molecules 1000mg/g
Adsorption of large organic molecules 280mg/g
pH in distilled water >8
Phosphate release 0.000001g/ml

The role of activated carbon in the reef aquarium

Why should charcoal be used in the reef aquarium ?

There are organic pollutants that can only be removed from reef aquarium water by activated carbon. The reef aquarium is a closed artificial ecosystem in which living creatures continually produce organic waste products made up of proteins, fats, carbohydrates, organic acids and phenols.

The decomposition of organic waste will increase the activity of many undesirable microorganisms in the aquarium, increase the total oxygen demand (BOD, COD) which will lower the redox potential, cause excessive production of CO2 by bacterial respiration which , ultimately, will lower the pH. In addition there will be an increase in nitrogen and phosphorus compounds encouraging the growth of harmful bacteria and possibly unwanted algae. Accumulated organic waste also has a significant effect on light penetration, especially in the blue and near UV spectrum stimulating coral growth.

Removing organic waste from the water is therefore crucial for the success of the aquarium. The use of a powerful skimmer, fine mechanical filtration and healthy biological filtration (nitrification and denitrification) allows the treatment of large organic particles and the last products of the organic decomposition process. However, there are many small organic particles that can only be removed with very fine micro filtration based on activated carbon.

REEF-SPEC™ Carbon 500ml

How does activated carbon filter water ?

Scientifically speaking, carbon removes organic matter from water through a physical process called adsorption. In a reef aquarium the sub-microscopic pores of activated carbon are the final step in the mechanical filtration process, absorbing organic molecules that are too small to be captured by the finest mechanical filters or removed from the water by the skimmer.

Adsorption can be seen as the adhesion of a molecule to a surface thanks to attractive forces. This takes place inside the sub-microscopic pores of the charcoal because the attractive forces between the organic molecules and the inner surface of the charcoal are much stronger than the attractive forces that keep them dissolved in solution. This phenomenon continues until the inner surface of the carbon is full and saturated with organic matter.

What is activated carbon ?

Activated carbon is an extremely porous material with a structure similar to a sponge but with a very large internal surface reduced to its physical size. It can be made from several organic materials with high carbon content such as coconut shells, walnut shells, lignite, bituminous coal or anthracite. The carbonaceous material is "activated" via physical modification and thermal decomposition in a furnace, under a controlled atmosphere and temperature. The activation process significantly increases the surface area per unit volume of a fine network of sub-microscopic pores that allows the activated carbon to function as a filtration material. The origin of the carbon and the activation process used determine the physical characteristics of the finished product. There are many grades of activated carbon, so they must be selected according to the uses for which they are intended.

What makes an activated carbon ideal for the reef aquarium ?

There are a large number of validated international tests to evaluate and compare activated carbons. However, the most significant parameters for selecting a carbon intended for reef aquariums arethe iodine numberAndthe methylene blue index. These two parameters measure the carbon's ability to adsorb all organic waste from a reef aquarium that is not removed by the mechanical filtration and protein skimmer. The higher the index, the more organic material will be removed from the aquarium per gram of activated carbon used. Both indices are equally important and should always be considered when analyzing the results.

Several manufacturers specify amolasses indexWhile molasses-sized molecules are removed by the protein skimmer, rendering this criterion obsolete for studying the compatibility of activated carbon with reef aquariums.

In the past coals had the reputation of releasing phosphates into the water which is not desirable in reef aquariums. Today the rate ofIphosphate releaseIs therefore much more considered. In reality, as long as the phosphate release rate is below a given level, differences below that level are not measurable in the reef aquarium and are therefore meaningless.

The cleanliness of the product is also studied and measured by the ash index. Lowest is best here because high levels indicate that a large amount of particles will be released into the water thus reducing the actual amount of carbon that can be used for filtration. Ash levels are often given by manufacturers but the easiest way is to look at the turbidity of the water when you pour the charcoal into it.

In addition to these important indicators, the overall efficiency of the coal will also depend on its physical characteristics such as theproduct density,THEASD, THEpore volumeand themesh size.

Activated carbon produced by lignite and anthracite are not recommended for reef aquariums due to excessive fine powder released into the water (which can lead to lateral line necrosis in some fish known as "HLLE" in English). Coconut or bituminous coal are much better.

Tips for using Reef-Spec Charcoal in the reef aquarium:

Carbon adsorption depends on good contact between carbon and water. An active but moderate passage of water will therefore increase efficiency. Too much flux will reduce the contact time and interfere with the adhesion process of the organic molecules to the carbon. A flow that is too strong can also cause the grains of carbon to wear out between them, which would release carbon into the water.

For the best results:

  • Remove the dust by rinsing the carbon under running water.
  • Because of the air trapped in the pores, the charcoal will float. You can soak the charcoal in osmosis water until all the air has escaped before putting it in the aquarium.
  • Position the charcoal in a place where the water flow is around 1,000 to 1,500L/h for 50g of charcoal.
  • Replace carbon every 1-2 months. Note: As the carbon begins to saturate with organic material, it may begin to adsorb trace elements from water.

User manual :

Removal of organic load and yellow tint:The recommended dosage of Reef-Spec Charcoal Red Sea is about 50gr (100ml) per 200L for 1-2 months in a moderately populated reef aquarium.

Post-medication treatment:The recommended dosage of Reef-Spec Charcoal Red Sea to adsorb drug residues is about 100gr (200ml) per 200L for one week.

Post-ozone treatment:The recommended dosage of Reef-Spec Charcoal Red Sea to remove residual ozone is 50gr for 50mg/h of ozone injection. The charcoal should be placed at the outlet of the ozone reactor or protein skimmer. The carbon should be replaced when it has reached approximately 50% of its original volume.


Iodine index:The test standard for estimating the adsorption capacity of small molecules is in the range of 10 Å to 15 Å. Recommended levels in reef aquariums are over 850mg/g but the higher the number the better the result.

Methylene Blue Index:The test standard for estimating the adsorption capacity of medium molecules is in the range of 10 Å to 40 Å. Recommended levels in reef aquariums are over 250mg/g but the higher the number the better the result.

Molasses index:This injudicious test for estimating the adsorption capacity of large molecules must be above 40 Å. There is no recommended level as these molecules are removed by the protein skimmer.

Ash level:It is a measure of the non-carbon content of the activated carbon. This is a dust that will be released into the water by the coal. The less, the better.

Release of Phosphates:It is a measure of the residual ortho-phosphates that can be released by the carbon in the aquarium. The less, the better. For reef aquariums they should be less than 10mg/Kg. The best coals are less than 2mg/Kg.

Product density:This is the density of the charcoal, expressed in g/ml.

TSA – Total area:It is the amount of pore surface area available for adsorption, for a given mass of carbon. It is measured using techniques such as BET nitrogen adsorption, expressed in units of m2/g. Recommended levels should be above 800m2/g.

Pore volume:It is the amount of macro, meso and micropores. The ratio between TSA and pore volume gives an estimate of the active surface in m2/ml.

Mesh size:This is the grain size range. For water treatment their size should be 0.6 x 2.4mm.

What they think
(and they are right...)

View the trust certificate
  • For further information on the nature of the review controls, as well as the possibility of contacting the author of the review please consult our CGU.
  • No inducements have been provided for these reviews
  • Reviews are published and kept for a period of five years
  • Reviews can not be modified: If a customer wishes to modify their review then they can do so by contacting Verified Reviews directly to remove the existing review and publish an amended one
  • The reasons for deletion of reviews are available here.

4.7 /5

Based on 19 customer reviews

  • 1
  • 2
  • 3
  • 4
  • 5
Sort reviews by :

Hervé C. published the 13/07/2022 following an order made on 06/07/2022


Très bien

Did you find this helpful? Yes 0 No 0

Marcel H. published the 10/04/2022 following an order made on 02/04/2022


Le meilleur

Did you find this helpful? Yes 0 No 0

Pierre G. published the 05/03/2022 following an order made on 27/02/2022


Au Top

Did you find this helpful? Yes 0 No 0

PATRICE B. published the 07/12/2021 following an order made on 29/11/2021



Did you find this helpful? Yes 0 No 0

Anonymous A. published the 27/11/2021 following an order made on 20/11/2021


Conforme à la description

Did you find this helpful? Yes 0 No 0

Anonymous A. published the 10/01/2021 following an order made on 30/12/2020


Pas encore testé l'efficacité du produit, mais avec Red Sea, je suis confiant...

Did you find this helpful? Yes 0 No 0

Anonymous A. published the 03/07/2020 following an order made on 28/06/2020



Did you find this helpful? Yes 0 No 0

Anonymous A. published the 13/05/2020 following an order made on 05/05/2020


Excellent , fait son travail

Did you find this helpful? Yes 0 No 0

Anonymous A. published the 09/04/2020 following an order made on 05/04/2020


Le meilleur charbon pour moi

Did you find this helpful? Yes 0 No 0

Anonymous A. published the 23/05/2019 following an order made on 17/05/2019



Did you find this helpful? Yes 0 No 0



19 reviews
6 points fidélité En achetant ce produit
soit un bon de réduction de
Tax included
In stock (3)