Loading
Clear
Water
The optimal choice for marine & reef aquariums
REEF-SPEC Carbon is available in four sizes: 100g /3.5 oz, 250g /9 oz, 500g /18 oz, and 1000g /35 oz. Its optimized granule size, combined with a micro- and macro-porous structure, delivers an exceptionally high total adsorption capacity and enables rapid removal of the specific organic pollutants found in reef aquariums.
REEF-SPEC Carbon features extremely low phosphate leaching and minimal ash content, while maintaining a stable pH and not affecting the aquarium water chemistry.
REEF-SPEC Carbon requires less frequent replacement than non–reef-specific or lower-quality carbons, making it a highly effective and cost-efficient solution for maintaining the highest water quality in marine and reef aquariums.
Specifications
and Main Features
0.6 – 2.3 mm flakes
Shape
0.48 g/ml
Density
1.04 ml/g
Pore Volume (PV)
1000 m²/g
Total Surface Area (TSA)
990 m²/ml
TSA/PV
1000 mg/g
Small organic molecules adsorption
280 mg/g
Large organic molecules adsorption
>8
pH in distilled water
0.000001 g/ml
Phosphate output
Rapid removal of organic pollutants
High total adsorption capacity
Ultra-Low phosphate output
Ultra-Low ash content
Suitable for Marine & Freshwater
Filter Bag included( 250g, 500g, 1000g)
Specifications
Main Features
0.6 – 2.3 mm flakes
Shape
0.48 g/ml
Density
1.04 ml/g
Pore Volume (PV)
1000 m²/g
Total Surface Area (TSA)
990 m²/ml
TSA/PV
1000 mg/g
Small organic molecules adsorption
280 mg/g
Large organic molecules adsorption
>8
pH in distilled water
0.000001 g/ml
Phosphate output
Rapid removal of organic pollutants
High total adsorption capacity
Ultra-Low phosphate output
Ultra-Low ash content
Suitable for Marine & Freshwater
Filter Bag included( 250g, 500g, 1000g)
Dosage and Usage Instructions
Usage guide
Usage Tips
Organic load & yellow tint removal:
The recommended dosage of Red Sea’s REEF-SPEC Carbon is approximately 50 gr (100 ml) per 200 L (50 gallons) for a period of 1-2 months for a moderately stocked reef aquarium.
Post-medication treatment:
The recommended dosage of Red Sea’s REEF-SPEC Carbon to adsorb medication residuals is approximately 100 gr (200 ml) per 200 L (50 gallons) for a period of a week.
Ozone post-treatment:
The recommended dosage of Red Sea’s REEF-SPEC Carbon to remove residual ozone is 50 gr per 50mg/hr of ozone injection. The carbon should be placed at the ozone reactor/ protein skimmer outlet. Carbon should be replaced once it has reached approximately 50% of its original volume.
The adsorption activity of the Carbon media relies on a good Carbon/water contact, and therefore moderately active water flow will increase the efficiency.
Strong water flow will reduce the contact time and interfere with the adhesion process of the organic molecules to the Carbon.
Strong water flow may also cause the granules to grind against each other, releasing Carbon material to water.
For Best results:
- Remove any fines, by rinsing Carbon under tap water.
- Due to air trapped in the pores Carbon will float, and therefore it is recommended to soak the Carbon in RO water until all of the air has been released.
- Place the Carbon in a location with an active flow of 1000-1500 lph (250-400 gph) per 50 gr carbon.
- Replace Carbon every 1.5 – 2 months. Note: When Carbon becomes saturated with organics, it may start adsorbing some of the trace elements from the seawater
Why Use Carbon
in a Reef Aquarium?
How activated
Carbon clears water?
What is activated
Carbon?
Which Carbon
is ideal?
Why Use Carbon in a Reef Aquarium?
Reef aquariums are closed ecosystems where organisms produce organic waste—proteins, fats, carbohydrates, acids, and phenols. If left in the water, these organics fuel unwanted microorganisms, increase oxygen demand, lower Redox potential, raise CO₂ levels, reduce pH, and encourage nuisance bacteria and algae. They also impair light penetration critical for coral growth. Strong protein skimming, fine mechanical filtration, and healthy biological filtration handle large particles, but many small organics can only be removed effectively with activated carbon.
How activated Carbon clears water?
Scientifically speaking, carbon removes organic compounds from water through a physical process known as adsorption. In a reef aquarium, the submicroscopic pores of activated carbon represent the final stage of mechanical filtration, adsorbing organic molecules that are too small to be captured by even the finest filter media or physically removed by protein skimming.
Adsorption can be described as the adhesion of molecules to a surface by attractive forces. Within activated carbon, this occurs inside its vast network of submicroscopic pores, where the attractive forces between the organic molecules and the carbon’s internal surfaces are stronger than the forces keeping those molecules dissolved in the water. This process continues until the available surface area is fully occupied and the carbon becomes saturated with organics.
What is activated Carbon?
Activated Carbon is an extremely porous material with a sponge-like structure and a very large internal surface area relative to its physical size. It is produced from a variety of organic materials with high carbon content, such as coconut shells, nutshells, lignite, bituminous coal, or anthracite. The Carbon-based material is “activated” through physical modification and thermal decomposition in a furnace, under a carefully controlled atmosphere and temperature.
The activation process significantly increases the surface area per unit volume by creating a fine network of submicroscopic pores, which gives activated Carbon its ability to function as an effective filter material. The source material and activation process determine the physical characteristics of the finished product. There are many different grades of activated Carbon, each designed for specific applications and performance requirements.
Which Carbon is ideal?
There are a number of internationally accepted tests for evaluating and comparing activated Carbon. However, the most significant parameters for selecting a Carbon for reef aquariums are the Iodine Number and Methylene Blue Number. These two parameters measure the ability of the Carbon to adsorb organic waste from a reef aquarium that is not removed by mechanical filtration or protein skimming. The higher the number, the more organics will be removed per gram of active Carbon used. Both of these numbers are equally important and should always be considered together when evaluating test data.
Some manufacturers quote a Molasses Number; however, molecules in the molasses size range are typically removed by protein skimming, making this number irrelevant when evaluating the suitability of activated Carbon for reef aquariums.
In the past, Carbons have been known to leach phosphate into the water, which is undesirable for a reef aquarium. Therefore, lower levels of Leachable Phosphate are preferred. In reality, as long as leachable phosphate is below a basic threshold, differences below that level are not measurable in reef aquariums and are irrelevant.
The cleanliness or dustiness of the product is also a consideration and is measured as the Ash Level. Lower ash levels are better, as higher levels indicate more particles released into the water and less active Carbon remaining to perform filtration. Ash levels are often quoted by manufacturers, but the easiest way to visualize it is by observing the turbidity when adding the Carbon to water.
In addition to these important indicators, the overall efficiency of activated Carbon will be affected by its physical parameters, such as Product Density, TSA, Pore Volume, and Mesh Size.
Activated Carbon produced from lignite and anthracite is not recommended for reef aquariums due to excessive fine powder released into the water, which may lead to lateral line necrosis (“HLLE disease”) in some fish. Coconut shell or bituminous coal are the preferred sources.
Technical terms
Iodine Number
Standard testing done to estimate the adsorption capacity of small molecules, in the range of 10 Å to 15 Å. Recommended levels for reef aquariums are above 850 mg/g but the higher the number the better.
Methylene Blue Number
Standard testing done to estimate the adsorption capacity of medium size molecules in the range of 15 Å to 40 Å. Recommended levels for reef aquariums are above 250 mg/g but the higher the number the better.
Molasses Number
Non-standard testing done to estimate the adsorption capacity of large molecules above 40 Å. There is no recommended level for reef aquariums these molecules are removed by protein skimming.
Leachable phosphate
A measure of the amount of residual orthophosphates PO4 that may leach from the Carbon to the aquarium. The less phosphate the better and for reef aquariums should be below 10 mg/kg. Highest quality Carbons will be below 2 mg/kg.
Ash Level
A measure of the non-Carbon content of the activated Carbon. This is normally a dust that will be released from the Carbon to the water. The less Ash the better.
Product Density
Density of the Carbon at maximum packing efficiency, reported in g/ml.
TSA – Total Surface Area
Amount of pore surface available for adsorption for a given mass of Carbon, measured using techniques such as BET nitrogen adsorption; reported in units of m²/g. Recommended levels are above 800 m²/g.
Pore volume
The amount of macro, meso and micro pores. The ratio between TSA to pore volume estimate the active surface area in m2/ml.
Mesh Size
Measure of particle size range of the granular product. Recommended mesh size for water treatment is 8 x 30 mesh (0.6 x 2.4 mm).
Why Use Carbon
in a Reef Aquarium?
How activated
Carbon clears water?
What is
activated Carbon?
Which Carbon
is ideal?
Why Use Carbon in a Reef Aquarium?
Reef aquariums are closed ecosystems where organisms produce organic waste—proteins, fats, carbohydrates, acids, and phenols. If left in the water, these organics fuel unwanted microorganisms, increase oxygen demand, lower Redox potential, raise CO₂ levels, reduce pH, and encourage nuisance bacteria and algae. They also impair light penetration critical for coral growth. Strong protein skimming, fine mechanical filtration, and healthy biological filtration handle large particles, but many small organics can only be removed effectively with activated carbon.
How activated Carbon clears water?
Scientifically speaking, carbon removes organic compounds from water through a physical process known as adsorption. In a reef aquarium, the submicroscopic pores of activated carbon represent the final stage of mechanical filtration, adsorbing organic molecules that are too small to be captured by even the finest filter media or physically removed by protein skimming.
Adsorption can be described as the adhesion of molecules to a surface by attractive forces. Within activated carbon, this occurs inside its vast network of submicroscopic pores, where the attractive forces between the organic molecules and the carbon’s internal surfaces are stronger than the forces keeping those molecules dissolved in the water. This process continues until the available surface area is fully occupied and the carbon becomes saturated with organics.
What is activated Carbon?
Activated Carbon is an extremely porous material with a sponge-like structure and a very large internal surface area relative to its physical size. It is produced from a variety of organic materials with high carbon content, such as coconut shells, nutshells, lignite, bituminous coal, or anthracite. The Carbon-based material is “activated” through physical modification and thermal decomposition in a furnace, under a carefully controlled atmosphere and temperature.
The activation process significantly increases the surface area per unit volume by creating a fine network of submicroscopic pores, which gives activated Carbon its ability to function as an effective filter material. The source material and activation process determine the physical characteristics of the finished product. There are many different grades of activated Carbon, each designed for specific applications and performance requirements.
Which Carbon is ideal?
There are a number of internationally accepted tests for evaluating and comparing activated Carbon. However, the most significant parameters for selecting a Carbon for reef aquariums are the Iodine Number and Methylene Blue Number. These two parameters measure the ability of the Carbon to adsorb organic waste from a reef aquarium that is not removed by mechanical filtration or protein skimming. The higher the number, the more organics will be removed per gram of active Carbon used. Both of these numbers are equally important and should always be considered together when evaluating test data.
Some manufacturers quote a Molasses Number; however, molecules in the molasses size range are typically removed by protein skimming, making this number irrelevant when evaluating the suitability of activated Carbon for reef aquariums.
In the past, Carbons have been known to leach phosphate into the water, which is undesirable for a reef aquarium. Therefore, lower levels of Leachable Phosphate are preferred. In reality, as long as leachable phosphate is below a basic threshold, differences below that level are not measurable in reef aquariums and are irrelevant.
The cleanliness or dustiness of the product is also a consideration and is measured as the Ash Level. Lower ash levels are better, as higher levels indicate more particles released into the water and less active Carbon remaining to perform filtration. Ash levels are often quoted by manufacturers, but the easiest way to visualize it is by observing the turbidity when adding the Carbon to water.
In addition to these important indicators, the overall efficiency of activated Carbon will be affected by its physical parameters, such as Product Density, TSA, Pore Volume, and Mesh Size.
Activated Carbon produced from lignite and anthracite is not recommended for reef aquariums due to excessive fine powder released into the water, which may lead to lateral line necrosis (“HLLE disease”) in some fish. Coconut shell or bituminous coal are the preferred sources.
Technical terms
Iodine Number
Standard testing done to estimate the adsorption capacity of small molecules, in the range of 10 Å to 15 Å. Recommended levels for reef aquariums are above 850 mg/g but the higher the number the better.
Methylene Blue Number
Standard testing done to estimate the adsorption capacity of medium size molecules in the range of 15 Å to 40 Å. Recommended levels for reef aquariums are above 250 mg/g but the higher the number the better.
Molasses Number
Non-standard testing done to estimate the adsorption capacity of large molecules above 40 Å. There is no recommended level for reef aquariums these molecules are removed by protein skimming.
Leachable phosphate
A measure of the amount of residual orthophosphates PO4 that may leach from the Carbon to the aquarium. The less phosphate the better and for reef aquariums should be below 10 mg/kg. Highest quality Carbons will be below 2 mg/kg.
Ash Level
A measure of the non-Carbon content of the activated Carbon. This is normally a dust that will be released from the Carbon to the water. The less Ash the better.
Product Density
Density of the Carbon at maximum packing efficiency, reported in g/ml.
TSA – Total Surface Area
Amount of pore surface available for adsorption for a given mass of Carbon, measured using techniques such as BET nitrogen adsorption; reported in units of m²/g. Recommended levels are above 800 m²/g.
Pore volume
The amount of macro, meso and micro pores. The ratio between TSA to pore volume estimate the active surface area in m2/ml.
Mesh Size
Measure of particle size range of the granular product. Recommended mesh size for water treatment is 8 x 30 mesh (0.6 x 2.4 mm).
REEF-SPEC Carbon Performance Comparison
Comparative test results between Red Sea’s REEF-SPEC Carbon and other leading brands
Overall
Rating
Iodine Number
mg/g
Methylene Blue
Number mg/g
Leachable
Phosphate mg/Kg
Cleanliness
Rating
Overall Rating
A
B
C
D
E
F
G
*Overall rating is based on the average score of the following 4 parameters.
Iodine Number mg/g
A
B
C
D
E
F
G
Methylene Blue Number mg/g
A
B
C
D
E
F
G
Leachable Phosphate mg/Kg
A
B
C
D
E
F
G
Cleanliness Rating
A
B
C
D
E
F
G
Note: Testing was conducted in Red Sea’s laboratory on single samples of several leading carbon brands, purchased randomly.
REEF-SPEC Carbon Performance Comparison
Comparative test results between Red Sea’s REEF-SPEC Carbon and other leading brands
Overall
Rating
Iodine Number
mg/g
Methylene Blue
Number mg/g
Leachable
Phosphate mg/Kg
Cleanliness
Rating
Overall Rating
*Overall rating is based on the average score of the following 4 parameters.
Iodine Number mg/g
*Overall rating is based on the average score of the following 4 parameters.
Methylene Blue Number mg/g
A
B
C
D
E
F
G
Leachable Phosphate mg/Kg
A
B
C
D
E
F
G
Cleanliness Rating
A
B
C
D
E
F
G
Note: Testing was conducted in Red Sea’s laboratory on single samples of several leading carbon brands, purchased randomly.
Performance Comparison
REEF-SPEC Carbon vs. leading brands: cleanliness performance results
User reviews
Dan Zada
REEFER XL 425
I love how it cleaned my water and made all the corals stand out. Cleaner water meant light can get better penetration to the darker parts of the aquarium and my corals are thriving.
I feel it even helped with the algae as I clean the front glass less. It costs less and lasts longer than what I used to use so it’s a win-win.
I replace it regularly and it keeps my water sparkling clean. One thing I like about it is that it’s much cleaner than other carbons with minimal washing needed and no dust waste particles getting caught in my skimmer after I place it in my system.
Liam Lovatt
MAX-S 650
Initially I thought “it’s just carbon” but after I tried it I was very impressed! It works very quickly and polishes the water really well.
On top of giving excellent results, it has a great removal capacity as you need a relatively small amount to get the job done. Its much cleaner to work with than all the other carbon I have tried. The filter bag is also an added bonus.
Over all I gave it a chance and glad I did, it’s here to stay.
Load more
Join our Facebook Group
The largest, fastest growing community of Red Sea reefkeepers sharing tips, experience & insights
Let’s reef!
Join our Facebook Group
The largest, fastest growing community of Red Sea reefkeepers sharing tips, experience & insights
Let’s reef!
