How to Use Activated Charcoal in a Terrarium

How to Use Activated Charcoal in a Terrarium

Activated Charcoal for a Healthier Terrarium Ecosystem

Terrariums have captivated plant enthusiasts for decades, offering a miniature world of lush greenery and intricate ecosystems. As these self-sustaining environments grow in popularity, one ingredient has consistently stood out as a game-changer: activated charcoal. This versatile material holds the key to unlocking the full potential of your terrarium, creating a pristine and thriving habitat for your plant companions.

So, Is Terrarium Charcoal Necessary?

Upgrade Your Terrarium Game Activated Charcoal for a Pristine Ecosystem
Terrarium charcoal

The short answer is: not necessarily. Terrariums can certainly function without the addition of charcoal. However, the benefits that charcoal provides make it a highly recommended inclusion for any terrarium enthusiast. By understanding the role of charcoal in these miniature ecosystems, you can elevate your terrarium game and create a truly captivating display.

The Potential Benefits of Charcoal in Terrariums

Upgrade Your Terrarium Game Activated Charcoal for a Pristine Ecosystem
Terrarium charcoals are great, but not necessary.

Charcoal is a versatile and powerful tool in the world of terrariums, offering a range of benefits that can transform the health and longevity of your living masterpiece. Let's dive into the key reasons why charcoal is a game-changer for terrarium enthusiasts.

Why Does a Terrarium Need Purifying?

Terrariums, by their very nature, are closed environments that can quickly become susceptible to the buildup of harmful substances. As plants metabolize and decompose, they release organic compounds, excess nutrients, and even toxins that can pollute the delicate balance of the system. Without a means of purification, these waste products can accumulate, leading to stagnation, mold growth, and ultimately, the demise of your terrarium inhabitants.

Enhancing terrarium drainage with charcoal

One of the primary benefits of incorporating charcoal into your terrarium is its ability to improve drainage. Charcoal, with its highly porous structure, acts as a natural filter, helping to remove excess water and prevent the soil from becoming waterlogged. This is particularly important in closed terrarium environments, where the lack of airflow can lead to soil compaction and poor oxygenation.

The role of activated charcoal in terrarium soil

Activated charcoal is a powerful addition to the soil in your terrarium. Its high surface area and adsorptive properties make it an effective tool for absorbing and trapping harmful substances, such as chemicals, heavy metals, and toxic compounds. By incorporating activated charcoal into the soil, you can create a protective barrier that helps to purify the water and maintain a healthy, balanced ecosystem.

Why is Activated Charcoal Superior in Terrariums?

Activated charcoal is the preferred choice for terrarium enthusiasts due to its unique properties. Unlike regular charcoal, activated charcoal undergoes a specialized process that increases its surface area and adsorptive capacity. This means that it can effectively trap and remove a wider range of contaminants, making it a more efficient and effective purifier for your terrarium.

Choosing the right charcoal for your terrarium

When it comes to selecting the right charcoal for your terrarium, there are a few key factors to consider:

Characteristic Ideal for Terrariums
Type of Charcoal Activated charcoal
Particle Size Fine to medium-sized granules
Source Hardwood or coconut shell
Purity High-quality, food-grade or aquarium-grade

An unordered list of additional considerations:

  • Avoid charcoal briquettes, which may contain additives and binders that can be harmful to your terrarium.
  • Choose a charcoal that is specifically marketed for use in aquariums or terrariums, as these are often screened for purity and safety.
  • Consider the size of your terrarium when determining the amount of charcoal needed, as larger containers may require more.
  • Ensure the charcoal is evenly distributed throughout the soil to maximize its effectiveness.

Counterpoints to Using Charcoal in Terrariums

Upgrade Your Terrarium Game Activated Charcoal for a Pristine Ecosystem
A terrarium jar with bioactive charcoal

While the benefits of charcoal in terrariums are numerous, it's important to acknowledge that there are some potential drawbacks or counterpoints to consider:

  1. Potential pH Imbalance: Charcoal can have a slightly alkaline pH, which may not be ideal for certain plants that prefer acidic soil conditions. It's essential to carefully research the pH requirements of your terrarium plants and adjust the soil mixture accordingly.
  1. Potential Nutrient Absorption: Charcoal's adsorptive properties can potentially absorb essential nutrients from the soil, depriving your plants of necessary minerals. To mitigate this, it's recommended to supplement the soil with a balanced terrarium-specific fertilizer.
  1. Aesthetic Considerations: Some terrarium enthusiasts may find the dark, gritty appearance of charcoal to be less visually appealing than a more uniform soil substrate. In such cases, alternative options like perlite or vermiculite may be preferred.
  1. Potential Overuse: While charcoal offers many benefits, it's possible to use too much, which can disrupt the delicate balance of your terrarium ecosystem. It's essential to follow the recommended dosage and not overload the system.

Unsuitable Forms of Charcoal for Terrariums

Upgrade Your Terrarium Game Activated Charcoal for a Pristine Ecosystem
Terrarium charcoal will work great if used accordingly

Not all forms of charcoal are suitable for use in terrariums. It's important to avoid the following:

  1. Briquettes: Charcoal briquettes often contain additives and binders that can be harmful to your terrarium plants and animals.
  2. Lump Charcoal: This type of charcoal can be too coarse and irregular in shape, making it less effective in the confined space of a terrarium.
  3. Charcoal from Unknown Sources: Charcoal from unspecified sources may contain impurities or contaminants that can negatively impact your terrarium's ecosystem.

Common misconceptions about using charcoal in terrariums

  1. Charcoal Alone Prevents Mold: While charcoal can help absorb excess moisture and some toxins, it is not a standalone solution for preventing mold growth. Proper terrarium maintenance, including adequate airflow and monitoring, is still essential.
  1. Charcoal Lasts Forever: Activated charcoal does have a finite lifespan and will gradually become saturated with contaminants over time. Periodic replacement or replenishment is necessary to maintain its purifying effects.
  1. Charcoal is a Substitute for Drainage: Charcoal should not be viewed as a replacement for proper drainage in a terrarium. It works in conjunction with a well-draining substrate to ensure optimal moisture management.

Check out our terrarium care guide: The Ultimate Terrarium Care Guide

Tips for incorporating charcoal into your terrarium design

  1. Layer the Charcoal: When adding charcoal to your terrarium, consider creating a distinct layer of charcoal at the bottom, topped with a layer of soil. This helps to ensure even distribution and maximizes the charcoal's effectiveness.
  1. Adjust the Amount: The ideal amount of charcoal to use in your terrarium will depend on the size of the container and the specific needs of your plant and animal inhabitants. A general guideline is to use about 1/4 to 1/2 inch of charcoal at the bottom of the container.
  1. Mix with Other Soil Amendments: Charcoal can be combined with other soil additives, such as perlite or vermiculite, to create a well-balanced and nutrient-rich substrate for your terrarium.
  1. Monitor and Maintain: Regularly check your terrarium for any signs of imbalance or excess buildup of contaminants. Occasionally, you may need to refresh or replace the charcoal to maintain its purifying effects.


Activated charcoal is a game-changing ingredient for terrarium enthusiasts, offering a wealth of benefits that can elevate the health and longevity of your miniature ecosystem. By understanding the role of charcoal in terrariums and incorporating it into your design, you can create a thriving, self-sustaining habitat that showcases the beauty and resilience of nature.

Whether you're a seasoned terrarium artist or just starting your journey, incorporating activated charcoal into your terrarium can be a transformative experience. Embrace the power of this versatile material and unlock the full potential of your terrarium, creating a pristine and captivating display that will inspire and delight.

Is activated charcoal essential for terrariums?

Activated charcoal can provide several benefits in a terrarium. While not strictly essential, it is a commonly recommended additive that can help maintain a healthier environment.

Can I use activated charcoal to purify water in my terrarium?

Yes, activated charcoal can be used in combination with a filtration system to help purify the terrarium's water source.

Is activated charcoal harmful to plants?

Activated charcoal is not harmful to plants. However, it is important to avoid over-use since excessive amounts can absorb essential nutrients.

Can I use activated charcoal in a bioactive terrarium?

Yes, activated charcoal can be used in a bioactive terrarium. As a natural material, it is safe for both plants and the beneficial microorganisms that inhabit the terrariums ecosystem.

How often should I replace the activated charcoal in my terrarium?

Activated charcoal should be replaced every 6-12 months, or whenever it becomes saturated and loses its effectiveness.
Back to blog

Leave a comment

Please note, comments need to be approved before they are published.