Activated Carbon for Plants, Terrariums, and Aquariums: A Natural Filter Solution
Activated carbon, also known as activated charcoal, is an essential addition to terrarium or houseplant soil. It helps filter out harmful substances like chemicals, metals, and mold, ensuring a healthier environment for your plants. When used in terrariums, it's typically placed just above the drainage layer to create an extra barrier of protection. Alternatively, it can be mixed directly into the plant soil to prevent the accumulation of harmful elements.
The versatility of activated carbon extends beyond plants—it's highly effective in aquarium filtration as well. This natural filtering agent is available in convenient, resealable bags for ease of use.
Key Benefits of Activated Carbon:

Mold Reduction: Helps reduce the growth of mold in both terrariums and soil environments.
Odor Prevention: Absorbs and neutralizes unpleasant smells, making it ideal for closed terrariums and aquariums.
Increased Surface Area: With 100x more surface area compared to regular charcoal, activated carbon maximizes its filtering capabilities.

Activated Carbon in Terrariums
Adding activated carbon to terrarium soil offers a protective layer for the root system, acting as a barrier against pests and mold. Although not a complete protection method, it significantly reduces the risk of mold and promotes healthier root development. The gritty texture it adds to the soil improves aeration, ensuring that excess moisture doesn’t stay trapped, which can lead to root rot.
Why Use Activated Carbon in Plant Soil?
Activated carbon is an excellent addition to both the soil and drainage layer of terrariums. Each time water flows through the soil, it is filtered through the activated carbon, effectively reducing the accumulation of harmful particles. Numerous tests comparing terrariums with and without activated carbon have shown a dramatic decrease in mold growth when carbon is used.
What Makes Activated Carbon So Effective?
The “activation” process involves treating regular charcoal at high temperatures, expanding it and creating small air pockets. These air pockets drastically increase the surface area of the carbon, making it about 100 times more effective at adsorbing harmful substances than regular charcoal. This expanded surface area is the key to its superior filtering power.
Conclusion
Activated carbon is an excellent solution for improving plant health in terrariums, houseplants, and aquariums. Its ability to reduce mold, control odors, and filter harmful substances makes it a must-have for plant enthusiasts.