Activated carbon is a valuable tool in the world of aquarium keeping, offering numerous benefits for your underwater ecosystem.
This magical ingredient has the power to eliminate chlorine, removes water discoloration, and even banish unpleasant odors from your aquarium.
Whether you’re new to fishkeeping or a seasoned aquarist, understanding how to use activated carbon in your aquarium can make a significant difference in maintaining a healthy and clear tank.
In this guide, I’ll delve into the various aspects of activated carbon usage, addressing key questions and providing essential tips along the way.
What is activated carbon?
Activated carbon, often referred to as activated charcoal, is a remarkable substance used for chemical filtration in aquariums.
This highly porous material is renowned for its ability to remove pollutants and enhance water quality, making it an indispensable asset for fishkeepers.
Precisely which pollutants does it target? In aquariums, activated carbon is frequently employed to eliminate:
- Chlorine and chloramines
- Tannins responsible for water discoloration
- Phenols that result in unpleasant odors
- Specific medications
But what exactly is it made of, and how does it benefit your aquatic environment?
What is activated carbon made of?
Activated carbon primarily consists of various organic materials, such as bituminous coal, peat, wood, and coconuts. Activated carbon is made in two main steps: carbonization and activation.
Carbonization
In the first step, called carbonization, the raw material is heated in a special way in an environment with no reactions, and the temperature is kept below 800 ºC. This process removes elements like oxygen, hydrogen, nitrogen, and sulfur from the source material.
Activation
After carbonization, the material (now called “char”) needs to be activated to create tiny holes in it. This is done by heating it again, but this time at temperatures between 800-900 ºC, while using air, carbon dioxide, or steam.
In the context of aquariums, it’s crucial to select the right type of activated carbon.
For optimal results, Granular Activated Carbon made from Bituminous coal is recommended.
This particular form of activated carbon possesses superior pore structure and is designed specifically for water treatment, ensuring optimal pollutant removal.
I wrote more information about the types below.
What does carbon do in a fish tank?
Activated carbon serves as a versatile solution in your aquarium, offering several key advantages for your fish and aquatic environment.
Here are some of the notable benefits.
Clarifies aquarium water
One of the primary benefits of using activated carbon is its ability to increase water clarity.
By effectively removing tannins, which can result from decaying plant matter or fish waste, activated carbon ensures a clear and visually appealing aquarium.
While tannins from certain sources may benefit your fish, preventing discoloration caused by organic waste is essential to maintain water quality.
Removes bad odors
Activated carbon is highly proficient at eliminating bad odors in your aquarium.
It targets phenols, which often arise from the breakdown of organic materials, such as live plants, fish waste, or uneaten food.
Over time, phenols can accumulate and lead to issues like lethargy in fish. Activated carbon not only restores a pleasant environment but also contributes to your fish’s well-being.
Removes chlorine and chloramine
Activated carbon effectively neutralizes chlorine and chloramine, both of which can be harmful to fish.
It is particularly valuable for aquarists using RO (reverse osmosis) water in their tanks, as it helps protect the water’s membrane integrity.
Some fishkeepers even prefer activated carbon over traditional water conditioners for dechlorinating their tank water.
Removes certain medications
Activated carbon can potentially absorb certain medications from the water, hindering their effectiveness in treating fish illnesses.
If you plan to medicate your fish, it’s advisable to remove activated carbon from your filtration system during treatment.
After treatment concludes, you can reintroduce activated carbon to remove any remaining medication from the water.
It’s essential to note that activated carbon does not remove ammonia, nitrites, or nitrates. To manage these toxins, regular water changes and a well-established nitrogen cycle remain crucial.
Can activated carbon in an aquarium harm or kill fish?
While activated carbon is generally safe for aquarium use, it’s crucial to use it judiciously, especially when medicating fish or maintaining water quality.
Follow dosing guidelines, choose quality products, and be attentive to the condition of your activated carbon to ensure the well-being of your aquatic inhabitants.
How long does activated carbon last?
Activated carbon is a highly effective filtration medium, but its efficiency diminishes over time.
Activated carbon typically lasts for two to four weeks, after which it becomes saturated and can no longer absorb pollutants.
Several factors influence its lifespan, including the level of pollutants in your tank, the quality of the carbon, and its placement within your filtration system.
High number of contaminants
If your aquarium contains a substantial quantity of pollutants, such as tannins, phenols, or other organic and inorganic substances, the activated carbon will reach its saturation point more quickly.
The limited surface area available for contaminants to attach to the carbon means that it can become oversaturated.
Low-quality activated carbon
Choosing high-quality activated carbon is vital, as low-quality variants often contain higher levels of phosphates and ash.
Low-quality carbon may deactivate sooner and prove less effective at removing pollutants.
Poor placement of carbon
To maximize the lifespan of activated carbon, it should be positioned within your aquarium filter after the mechanical filtration stage.
This allows it to purify the water as soon as it enters the filter, minimizing the risk of debris buildup that can lead to quicker deactivation.
What can’t activated carbon do?
While activated carbon offers numerous benefits, it’s essential to understand its limitations.
Activated carbon cannot remove ammonia, nitrites, or nitrates from aquarium water.
These compounds are integral components of the nitrogen cycle and require other methods, such as regular water changes and biological filtration, for effective removal.
Activated carbon also does not remove heavy metals, such as iron. If your water source contains these metals, it’s advisable to use a water conditioner before adding water to your aquarium.
Activated carbon is also not effective for removing tannins from water. If you want to remove extra tannins from the water, you should use Purigen. This is a reusable product and in the long run it will be cheaper.
Beneficial bacteria that accumulate over the time activated carbon is used will be thrown away anyway.
When you throw away the cartridges, you are throwing away the beneficial bacteria. It is better for beneficial bacteria to grow in some kind of sponges and other porous media.
Generally, I only use activated carbon to remove meds from water. Fish tanks don’t really need carbon unless you’re trying to remove something from the water. It is better to use a sponges as a filtering material.
How to reactivate carbon? Is it possible?
Activated carbon is a chemical media that absorbs substances from water. Its service life span is therefore limited. Depending on how much work it has to do, it can last up to a week.
I may even say that after using it for 3 months, it becomes practically useless.
So Can you reuse your activated carbon? No.
Activated carbon is not a material that can be “recharged” or “reactivated” by methods like heating in an oven.
I once came across information online suggesting that reactivation is possible, but I have never tried it myself and absolutely do not subscribe to it.
I would just buy more. The general guide assumes that after a month they are already used up.
If you need more activated carbon, just buy more. I believe that there is absolutely no use in saving old carbon.
Once the pores of activated carbon become saturated with trapped pollutants, it is no longer suitable for use and should be disposed of.
What are the different types of activated carbon?
Activated carbon comes in various forms, and selecting the right type is crucial for optimal performance in your aquarium. The most common types include:
- Granular Activated Carbon (GAC): Ideal for aquarium use, GAC offers excellent pollutant adsorption properties and is recommended for its effectiveness.
- Bead-Activated Carbon (BAC): Less common in aquariums, BAC consists of small beads and is used in specific applications.
- Extruded Activated Carbon (EAC): EAC is less porous than GAC and is typically employed in industrial processes rather than aquariums.
- Powdered Activated Carbon (PAC): PAC is often not recommended for aquarium use as it can pose risks to fish if not properly contained within a media bag.
Choosing GAC made from Bituminous coal is the preferred option for most aquarium setups, as it provides superior pollutant removal and water treatment capabilities.
Why opt for this particular activated carbon variety?
Well, this activated carbon boasts an exceptional pore structure tailored for top-notch pollutant removal in water treatment.
If you’ve got a water filter for your drinking water, chances are it’s equipped with Granular Activated Carbon crafted from Bituminous coal. Don’t compromise!
And I truly emphasize this point.
You might come across carbon pellets and beads in pet stores, serving as aquarium filter media, but they’re made from various materials.
Don’t be tempted by their lower prices – they’re not the right tools for the job. These alternative carbon types not only do a poorer job at removing pollutants but can also get clogged up faster.
Before I move on, there’s one more thing to note – some types of activated carbon contain phosphates.
If your carbon filter contains phosphates, they can seep into your aquarium, which is particularly problematic for freshwater tanks.
Many types of algae thrive on phosphates, and elevated phosphate levels often lead to algae taking over your entire tank.
If your test kit reveals high phosphate levels in your tank and you can’t find another reason for it, consider removing your carbon filter – it might be the source of the issue.
How to use activated carbon in an aquarium?
Using activated carbon in your aquarium can significantly enhance water quality, remove impurities, and contribute to a healthier aquatic environment.
But how to effectively use activated carbon in your aquarium?
Before you start, make sure you have the following materials ready:
- Activated Carbon
- Mesh Bag or Media Container
- Clean Water
Purchase high-quality activated carbon designed for aquarium use. The type and amount of carbon you need depend on your tank size and specific requirements.
You’ll need a mesh bag or a media container to hold the activated carbon within your filter. This prevents loose carbon particles from entering the tank.
Ensure you have clean, dechlorinated water on hand for rinsing the activated carbon.
New activated carbon often contains dust and fine particles that can cloud your aquarium water. To remove these impurities, follow these steps:
- Place the activated carbon in a fine mesh bag or media container.
- Rinse the carbon thoroughly under running water. Use dechlorinated water or old aquarium water to avoid introducing chlorine into the filter media.
- Continue rinsing until the water runs clear, indicating that most of the dust and impurities have been removed.
Activated carbon should be positioned in your aquarium filter after the mechanical filtration media (such as filter floss or sponge).
This placement allows the water to pass through the mechanical filter first, removing larger debris and preventing the activated carbon from clogging prematurely.
Open your filter compartment and place the mesh bag or media container containing the rinsed activated carbon inside. Ensure it fits securely and won’t shift during operation.
If you’ve treated your aquarium with medications, it’s essential to remove the activated carbon during treatment.
Activated carbon can absorb medications, rendering them ineffective.
Once the treatment is complete, you can reintroduce the activated carbon to help remove any residual medication from the water.
Incorporate routine maintenance into your aquarium care schedule. This includes regular water changes, cleaning mechanical filtration media, and monitoring water parameters.
Activated carbon is a valuable tool for maintaining water quality, but it should complement, not replace, essential aquarium maintenance practices.
How much activated carbon to use per gallon in an aquarium?
Determining the appropriate quantity of activated carbon for your aquarium depends on its size and specific needs.
Here is a general guideline for dosing activated carbon in your aquarium:
Use approximately 0.5 cups (around 120 milliliters) of activated carbon to 10 gallons.
So for 30 gallons you can use 1.5 cups of activated carbon.
These recommendations provide a general idea of the amount of activated carbon to use per gallon in your aquarium.
However, it’s essential to consider factors such as the level of pollutants, the carbon’s quality, and the specific requirements of your aquatic inhabitants.
Most activated carbon products include dosage instructions on their packaging for your convenience.
Does activated carbon affect ph in an aquarium?
Activated carbon typically has a minimal impact on aquarium pH levels. While it may have a slight acidifying effect, this influence is generally negligible and should not significantly alter your tank’s pH.
The slight acidification occurs because activated carbon can remove small amounts of organic acids and compounds from the water, which, in turn, can lead to a minor decrease in pH.
However, this effect is usually not a cause for concern for most aquariums, especially if you are using activated carbon correctly and in moderation.
Does activated carbon affect water hardness in an aquarium?
Activated carbon generally has no substantial impact on water hardness. It primarily focuses on adsorbing organic and inorganic pollutants and does not alter water hardness parameters.
Water hardness is mainly influenced by factors such as the mineral content of your water source and the composition of your substrate and decorations.
Activated carbon does not add or remove minerals responsible for water hardness.
Therefore, if you need to adjust water hardness in your aquarium, you would typically use other methods, such as adding minerals or using specific types of substrate.
Best kinds of activated carbon to use in an aquarium
Selecting the right activated carbon is crucial for achieving optimal results in your aquarium. Here are some of the best activated carbon products that you can trust for your tank:
MarineLand Black Diamond Premium Activated Carbon
Marineland Black Diamond Premium Activated Carbon 22 Ounces, Filter Media For aquariums
Marineland’s Black Diamond Premium Activated Carbon is your go-to solution for chemical aquarium filtration.
It excels at removing odors, discoloration, and impurities, leaving your aquarium water clear and sparkling.
This activated carbon is specially formulated with heat-activated bituminous coal-based carbon for superior performance.
It’s compatible with all types of aquarium filters, making it a versatile choice for various setups.
Fluval Carbon Filter Media
Fluval Carbon Filter Media for Aquariums, Premium Bituminous Carbon Inserts, 100-gram Nylon Bags, 3-Pack, A1440
Fluval is a reputable brand, and their carbon filter media is a reliable choice for maintaining clean and clear aquarium water.
The Fluval Carbon Filter is a versatile and efficient solution compatible with various Fluval filter models.
It features premium, low-ash carbon for excellent impurity absorption, improving water clarity and eliminating odors in both freshwater and saltwater aquariums.
Each pack includes three 100-gram nylon bags, suitable for most canister filters. Replace every four weeks for optimal results.
Aquapapa Activated Carbon Charcoal Pellets
AQUAPAPA 6 lbs Carbon Charcoal Filter Media Pellets in 6 Mesh Bags for Aquarium Fish Tanks
These carbon pellets are a fantastic choice for maintaining clear and pure aquarium water. They effectively remove odors, discoloration, and impurities, suitable for both freshwater and saltwater tanks.
The pellets are fast-acting and durable, with a 4mm diameter known for its efficiency. The package includes 6 lbs of bituminous carbon divided into 6 reusable zipper mesh bags, each containing 1 lb of carbon.
A crucial reminder: rinse the carbon media thoroughly before use for best results. The mesh bags are neatly packed inside a plastic bag for convenience.
AquaClear 70 Activated Carbon Inserts
AquaClear 70 Activated Carbon Inserts, Aquarium Filter Replacement Media, 3-Pack, A1386 , White
The AquaClear Activated Carbon Filter Inserts are a highly effective solution for maintaining water quality in aquariums.
They are compatible with AquaClear 70 Power Filters and offer impressive water clarification and odor removal.
The inserts feature premium, low-ash carbon with excellent porosity, ensuring efficient impurity absorption.
They work well in both freshwater and saltwater tanks up to 70 Each pack includes three inserts, and it’s recommended to replace them every four weeks for optimal results.
In Conclusion
Activated carbon is a valuable asset for maintaining a clean, clear, and healthy aquarium environment.
When used correctly, it can significantly enhance water quality, remove pollutants, and contribute to the well-being of your fish and aquatic inhabitants.
By understanding its properties, limitations, and proper usage, you can harness the full potential of activated carbon and enjoy a thriving aquatic ecosystem.
