The “Carbon Is Carbon” Fallacy

 After a roommate moved out and “gifted” me a Jaguar Cichlid tank and planted tetra tank in 2005, I quickly realized I had discovered a real-world application of science for which I had been searching. As more and more tanks were added I knew I had found MY FOREVER HOBBY. When I discovered activated carbon, it seemed like a cheap, miracle solution that allowed my tanks to look great overnight without spending the time on maintenance. It seemed like a time saving hack of the system. Several years in, almost at the same time, the plants in my lush planted tank began showing signs of deficiency while my prize sailfin tang began to show signs of Hole-in-head/Lateral Line Disease (HLLD). My first reaction thought it had to be contamination, so I naturally upped the dose of activated carbon. After hours of research, I discovered both these issues were caused by the thing I least expected: activated carbon. I cut carbon completely from my maintenance and replaced it with hours of husbandry. Adopting the mantra “water changes are free therapy”.

It was not until I discovered AquaChar in 2018 that I began using carbon in my aquariums again. The number of options and varieties of activated carbons is overwhelming to the average hobbyist. We consider the use of activated carbon complementary to AquaChar. If you desire, the proper use of reputably sourced activated carbon is a beneficial routine for quick adjustments in combination with the use of AquaChar. Before discussing what makes AquaChar different, I want to establish a baseline of understanding why the concept “carbon is carbon” is so complicated.


Activated carbon: A high purity amorphous carbon that is “activated” by attaching oxygen to the ends of the carbon molecules to create a quick adsorption reaction.

According to a 1959 issue of Tropical Fish Hobbyist, the game changing introduction of chemical filtration through activated carbon allowed scientists to “finally keep marine aquaria alive for months…”. Chemical filtration completed the trifecta with mechanical and biological that allowed hobbyist to grow the variety of animals we keep today. Activated carbon was being used for a quick reaction in medical uses which allowed for a rapid removal when added to water. The short lifespan led to the introduction of resins with carbon to adsorb the leaching associated with long term use leading to “finally we can keep marine aquaria for a year… possibly more”.

Activated carbon is designed to rapidly strip everything. After a 2-3 weeks the interaction with water has been covered by organics and had begun to develop a biofilm. Over time those organics begin to rot and create a septic zone with little flow. Leaving more activated carbon in for longer than the initial reaction was my problem. As the food source is diminish the bacteria begins to break down and release stored “pre-smoke” resins into the water. These same tars can also be released into the water through unwashed “fines” that are a byproduct of the industrialized mass production process.

Video showing porosity and what activated carbon does


Because of the wide variety of uses the production of activated carbon quickly became an industrialized process – driving down prices with mass production to increase barriers of entry for competitors. The process of making activated carbon requires costly external energy to reach the temperatures needed for the reaction. The high costs of fuel have led scientists to come up with “work around” processes to increase profitability. This is a general description of the process:

Carbonization: Heating the source material to push our stored moisture and gasses to weakens the bonds. This low energy process sets up the next step.

Crushing: To increase surface area, the pre-carbonized material is the sent through a grinder to create a powder and flakes. 60% of the activated carbon market is powder.

Pyritization: The next step is intended to get the source carbon red hot in a large tumbling tube to increase the carbon content while burning off the tars. This is the costliest part of the process.

Acid Washing: To reduce the time and temperature of external fuels companies with use a hydrochloric acid formula to remove the remaining surface tars and impurities. “Etching” the surface cleans the micropores for activation.  

Granularization: At this point flakes are sent to steam-activation and the powder is typically made into a paste to be pressed. This allows for larger, universally sized granules.

Steam-Activation: This high temperature step is where a proprietary chemical formula is used to “activate” the carbon. In this step is where the versatility in formulation occurs.

Get an idea of this process here:

The Machine

Activated Carbon Production Process

Industrial Carbon Production Plant


Much of discussion on types of source carbon revolves around micro-, meso-, and macro-porosity which, in my opinion, is good information but does not hold real application value. Carbon with mostly micropores would be a flat surface with a rapid reaction for a short period where mostly macropores would have a less potent, longer reaction. Micropores are the major contributor to the internal surface area while the meso and macropores are like the highways into interaction with water.

In the aquarium industry most of the activated carbon conversation is focused on fossil coal source carbons. The marketing behind this is that the process of fossilization compresses the carbon to make it easier to create the micropores at a lower temperature. Lignite is compressed peat and considered “low grade and soft”. Bituminous is compressed lignite that contains a tarlike substance call bitumen (better known as asphalt). Sustainable organic carbons like coconut account for nearly 60% of the market share because of the environmental regulations in industries like mining or wastewater remediation.

When mass production occurs on this scale, incremental solutions in the production process can lead to millions of dollars in cost savings. The switch to fossil coal as a source carbon presented a significant advantage. It eliminates the pre-carbonization step to shortening the duration of the process. They require significantly less external energy during burning due to the stored fossil fuels which cuts production cost. Typically sold by weight so there is a delicate balance between time, temperature, and oxygen to ensure profit is not burning away.


All activated carbon sold in the aquarium market is just a small portion of production formulated for another industrial use. Outside of AquaChar, there are not any specific carbons that is specifically made for the Aquarium Market. Activated carbon was originally designed for large-scale municipal use or removing poisons through dialysis and stomach pumping. One tablespoon (about 10 grams) accomplished what to a kilogram of charcoal could adsorb.

Municipal grade activated carbon is the reason we can trust your tap water to be clean and clear. It is designed to have more meso and macro porosity to increase the usable lifespan by catching the yellowing decayed organics inside of a large reaction chamber. Typically, part of a routine maintenance schedule where exhausted product is sent to a regeneration site to be acid-washed and steam activated for repeat use leading to a huge cost savings. It is designed to remove the fine organics from water over a longer period without the rapid stripping of the water column.

Medical grade was designed for maximizing micropores to create a rapid reaction that was revolutionary when time is a matter of life and death. This type of activated carbon is best used in situations where contamination is a concern and there is worry of immediate, detrimental impact on the inhabitants.

THINGS TO CONSIDER: Municipal grade as a wide range of acceptable qualities. We are using something meant for regeneration as a one-time use commodity. Typically, medical products typically have an expiration date. Rarely do you see an expiration date on the label of “medical-grade” carbons. Expiration dates usually means that it has a shelf life which means the reaction can diminish over time. Purchasing from a reputable company is essential to avoid “almost expired” products being repackaged at a premium.

Regeneration Process


While AquaChar is a completely different process, traditional activated carbon products have made the idea that “carbon is carbon” accurate on the market today. Here are some parting recommendations when looking at activated carbon:

Run the proper dose, but for no more than 2-3 weeks: ACTIVATED CARBON IS MEANT TO WORK FAST! When used properly it is a short-term solution to quickly provide a solution. Once it added to water it begins to magnetically pull in organics and pancake then to the surface. It does not take long for a biofilm to form which completely blocks interaction with water. Overdosing does not make it last longer but does run the risk of stripping the nutrients your system needs to survive.

Purchase quality sourced carbon from a reputable aquarium company: None of the activated carbon used are formulated specifically for aquariums. When a reputable company that puts their reputation behind branding a product, they have spent the time doing the testing before introduction. Because the use determines quality, if the price is low there were likely short cuts in production and/or testing. Buy from companies that will answer your questions and provide information.

There is no substitute for proper husbandry: I can not stress enough! Measuring your own individual experience when making any changes to your system is the key to success. Products like activated carbon is not a substitute for water changes, but a complementary product to have in your arsenal for specific targeted use.

Adding too much for too long was the source of my issues. Tars on the fine dust of cheaply sourced activated carbon caused the HLLD. The rapid reaction was able to outcompete the plant’s ability to store nutrients to caused signs of deficiency.  

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