What is a Bioactive Terrarium? (+ How to Make One)

Turning your terrarium bioactive is a natural way to enhance your plant ecosystem.

With the right bioactive setup, you can add years to your terrarium’s lifespan and significantly improve its health and vibrancy in the process. All with the aid of some of Mother Nature’s helpers.

Enter our bioactive bugs, microorganisms, and fungal mycelium.

These beneficial custodians (and colonies) are essential for your terrarium’s ability to self-regulate in the long term, and together they can take your biome closer to being fully self-sufficient. 

In this article, I’ll take you through my process of how to make a bioactive terrarium, so you can take your tropical ecosystem to the next level.

Let’s get into it.

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Crafting a Bioactive Terrarium: 3 Essential Elements

A bioactive terrarium is a closed ecological system that recycles organic material for the nourishment of the plants inside.

Something of a self-sustaining terrarium, if you will.

Through the addition of some key bioactive elements, we can entrust the terrarium with the dirty work of cleaning and restoring itself. Leaving us free to enjoy the laidback parts of terrarium life.

As you might expect, there are various factors involved in a successful bioactive ecosystem. But on a practical level, it’s mostly a one-time setup.

Simply add the right things in the right way, and the system will often work out the details by itself.

As the great Jeff Goldblum once said, “Life finds a way.” 

bioactive terrarium full of wild growth
Here’s one of our oldest bioactive terrariums that was left unopened for over a year. Wild in every sense of the word!

These three bioactive elements transform a regular setup into an effective bioactive terrarium.

  1. Bioactive substrate – The bioactive cycle thrives on available organic material, so these will need to be supplied to the terrarium in some form. Depending on your material(s) of choice, you can mix them in as part of your substrate mix and/or add them on top as a supplement.
  2. Microfauna – We’ll be talking a LOT about microfauna, our beneficial terrarium bugs often referred to as the ‘clean-up crew.’ Their primary function is to break down organic matter and convert it into nutrients for your plants. 
  3. Microflora – Bacteria and fungi play a pivotal role in the natural world, and they can be put to good use in terrariums, too. Like microfauna, they efficiently decompose waste material and return goodness in its stead. 

1. Bioactive Substrate – The Best Mixes and Materials

A well-balanced bioactive substrate should be able to support all life in your terrarium.

So that means all the usual qualities of good water retention, aeration, and drainage needed for healthy plants. Plus, the nutrition and dwelling needs of your bug, bacteria, and fungal colonies.

Fear not; it’s just about getting the right mix of ingredients to provide the necessary fertile grounds.

Your ideal bioactive substrate mix will somewhat depend on your plant choice, though there are some well-rounded mixes that always hit the mark.

Any version of the classic ABG mix is a good place to start. We have our own take on it, which you can buy from the shop!

👉 Shop our terrarium substrate mix.

These are some key bioactive ingredients to look out for:

  • Charcoal is a fantastic ingredient for bioactivity, as its high surface area makes it easy for microbes to colonize and provides an effective feeding ground for your microfauna.
  • Earthworm castings are my go-to material in providing easily digestible organic matter that can serve as the fuel source for your cleanup crew. (FYI, peat moss is the material used for this purpose in the classic ABG mix, but it’s not a renewable material, so I don’t recommend it – we use earthworm castings in our mix). 
  • Leaf litter can be whole added on top, or crushed up and mixed into the substrate. You can grab a bag of leaf litter on our shop, too.

Now, that’s by no means an exhaustive list. There are plenty of other things you could consider adding to round out a more complex mix (e.g., calcium sources for your bugs), but the basics will get you most of the way there.

2. Microfauna – The Best Bioactive Terrarium Bugs

Now we’re deep diving into the most exciting of the holy bioactive trinity – the bugs!

First and foremost, your custodial critters will be breaking down organic matter to nourish the soil. They’re the recycling dream team of your ecosystem – doing all the heavy lifting for you.

Which kinds of terrarium bugs are best, you ask?

Well, you actually have a lot of options when it comes to selecting your staff. Though the functions performed are often similar, there are different critters for different occasions.

Let’s take a look.


Springtails are the most popular option when considering what custodial critters to bring into the fold.

And for good reason.

These tiny detritivores are the perfect mold-munching machines, and they are small enough to be a good fit for almost any sized terrarium.

Plus, they’re cheap and easy to get your hands on – there’s really no reason not to use them in every project. You’ll thank me later.

👉 Grab one of our springtail cultures today!

An added bonus is their ability to jump incredible heights using their tails (hence the name). It’s not relevant, but no other insects on this list can do that.

So, 1-0 to the springtails.


Isopods (aka pill bugs) come in many sizes and often sport striking visuals.

A growing fascination with these critters has spawned a dedicated hobbyist culture, and I can see why!

powder orange isopods in terrarium
Here’s one of our terrarium favorites – the Powder Orange Isopod.

Though the adorable ducky isopods are very tempting, from a bioactive terrarium perspective, there are arguably some more appropriate/ readily available choices. 

For both small and large terrariums, Dwarf White Isopods and Dwarf Purple Isopods are equally great choices. They’re tiny, breed quickly and easily, and make short work of any decaying organic matter. 

Dwarf white isopods are serious bioactive pros in a tiny package.

Alternatively, if you’d like an isopod species with a bit more character – and even more appetite – consider the likes of Porcellio laevis, the appropriately named Dairy Cow Isopod (which is very popular as a feeder insect in bioactive reptile enclosures).

👉 Shop our full range of colorful isopods for sale here.

All of our bioactive species are helpfully labeled with a “clean up crew” tag.

Isopods make excellent partners with springtails in a cleanup crew too. They work together synergistically, so there’s no reason not to employ both!

Worms and Millipedes

Okay, so worms and millipedes can absolutely serve as bioactive custodians in terrariums.

But they come with some bigger caveats than the classic isopods and springtails wombo combo.

For starters, both millipedes and worms tend to be on the larger side. So they’re going to need a suitably large bioactive tank to house them. Terrarium worms require a much greater substrate depth, too.

Plus, they’re both heavy substrate feeders.

Which means you’d be refreshing your substrate a lot more often using these critters (which somewhat defeats the point of a self-sustaining terrarium). 

Finally, in the case of millipedes in terrariums, they’re also more temperature-sensitive than isopods and more likely to snack on your plants.

So, in most cases, they’re the inferior choice, but with the right setup and attitude, you can make it work.

On the plus side, the tunneling actions of both critters help to aerate the substrate. Worms do tend to make a mess on the glass while doing it, though. 

3. Microflora – How to Add Beneficial Colonies

Beneficial bacteria and fungi colonies are the icing on top of the cake.

It’s their role to finish the cycle of decomposing organic material (once the likes of springtails and isopods have munched the bigger blocks down to size).

Though these microbial colonies don’t see as much direct use in the industry as our tiny heroes, the springtails, they’re even easier to incorporate and bring a whole new set of benefits. 

Plus, a strong mycelium network – that’s the fancy name for fungal threads – leads to healthy root growth, and the fungi itself can be a food source for your bioactive critters.

It’s a win-win situation, and it’s as simple as mixing a microbe-filled powder into your substrate.


👉 Grab a Microbial Soil Builder right here.

Bioactive Terrarium Setup & Care Considerations

Finally, creating a bioactive terrarium isn’t just about adding the right bugs and colonies.

You’ll also need to nail the terrarium fundamentals to create a sustainable foundation for your ecosystem. Here are some other things to consider.

  • Containers – Make sure you have a terrarium container that’s large enough to house a colony of your chosen bioactive bugs. Most containers are suitable for springtails but not necessarily for isopods. 
  • Plants – Though there’s no such thing as a “bioactive terrarium plant,” there are some considerations when it comes to plant picks. For starters, some cleanup crew species are known for favoring plants as a snack, so I’d avoid those in your favorite planted setup (or opt for hardier plants that they don’t like – soft ferns are often a favorite). 
  • Moisture and humidity – Both springtails and isopods require consistent access to moisture (isopods are crustaceans, after all) and typically need lots of humidity. So, in most cases, tropical conditions are required for bioactive enclosures. However, dryer bioactive terrariums can be done with the right species. 
  • Ventilation – Though preserving humidity is important, you’ll likely need some fresh airflow in there for the critters to survive (definitely in the case of isopods). So, using a vent or partial lid can be a good idea, or you can just make sure to open it periodically.
  • Feeding. Your microfauna colonies will naturally grow and shrink depending on the abundance of food available. However, you may need to supplement with other foods to maintain healthy colonies (especially in the beginning). Check out our respective guides to springtail foods and isopod foods, or go ahead and sprinkle some of our Superfood concentrate to give them an instant boost.

Over to You

So, there we have it. A comprehensive guide to the bioactive terrarium. Now, it’s over to you to give it a try.

Tell me, which microfauna do you think you’ll try out, or are there any I’ve missed that you’re particularly fond of? Leave a comment below. 

Next up, check out our How to Make a Terrarium (Beginner’s DIY Guide).

3 thoughts on “What is a Bioactive Terrarium? (+ How to Make One)”

  1. The whole explanation as how to make a real ecosystem is great. I am a beginner, and this is what I was looking for: not only beautiful terraria, but a natural real balance within.
    Thank you!
    Diana Auvert

    1. That’s a really good question. In an ideal world you’d get your microflora “dose” evenly disributed through the substrate, but that’d require you dig everything up (and sprinking on top won’t work). If you have any access, I’d probably just try to mix a small amount into a patch of substrate and let it distribute iteslf as it grows.

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