Terrarium Cleanup Crew: How Isopods & Springtails Work Together

In a bioactive terrarium, waste is unavoidable.

Leaves fall, roots die back, and decaying organic matter slowly builds up in warm, humid conditions. Left alone, that decay doesn’t just disappear – it accumulates, feeds mold, and starts to destabilise the system.

That’s where terrarium cleanup crews come in.

Isopods and springtails are common tag-team partners because they tackle different parts of the same problem. One works on the visible, structural mess; the other operates almost entirely out of sight.

Together, they help keep decomposition moving instead of piling up.

This guide explains how that partnership actually works in a bioactive terrarium – what each contributes, why they’re often paired, and when that combination makes sense (and when it doesn’t).

A cleanup crew isn’t about removing waste from a terrarium – it’s about processing it.

In natural ecosystems, dead plant material doesn’t magically vanish. It’s broken down gradually, moving through different stages of decay until its nutrients are returned to the soil.

A bioactive terrarium relies on that same process, just compressed into a much smaller, more controlled space. Without organisms to handle this work, organic material tends to linger, rot, and mold over.

Cleanup crews exist to keep that cycle moving.

They fragment and/or consume organic matter, regulate microbial growth, and prevent waste from bottlenecking at any single stage.

When they’re doing their job properly, decomposition stays steady, subtle, and (mostly) invisible.

Isopods handle the heavy lifting.

They feed on larger pieces of organic material like leaf litter, decaying wood, and fallen plant matter – the stuff that would otherwise sit on the surface or slowly rot in place.

By chewing and fragmenting this material, isopods increase its surface area, making it easier for microbes and other organisms to finish the job.

Anything they do consume themselves is released back into the substrate via their fertilizing poop (also known as “frass”). It’s a win-win situation.

What’s important to understand is that isopods don’t “clean” in the household sense. They don’t eliminate waste – they convert it into forms the rest of the system can use. Or at least into smaller forms that the next species can tackle.

On their own, though, they leave gaps. Finer decay and mold growth often occur at a scale they simply don’t interact with.

That’s where springtails come in.

Springtails work at a much finer scale.

Rather than breaking down visible debris, they operate in the thin layer where moisture, microbes, and decaying material overlap.

Their primary role is grazing – feeding on fungi, algae, bacteria, and biofilms that develop as organic matter begins to soften and break down.

This matters because those early microbial blooms are often what cause problems in terrariums.

Mold doesn’t usually appear because something is “wrong.” It appears because moisture and organic material have created ideal conditions for fungal growth. That’s somewhat unavoidable in a closed terrarium setup (mold spores are literally everywhere).

Springtails help regulate this phase of decay by continuously grazing across damp surfaces and substrate particles, preventing fungal populations from concentrating in any one spot. Growth stays thin, dispersed, and short-lived rather than dense and persistent.

(They’re also pretty good at out-competing any pesky mites and fungus gnats).

In a functioning cleanup crew, springtails act as the system’s fine control layer – keeping fungal and microbial activity in check while larger decomposers handle the bulk of the work.

Using isopods and springtails together isn’t always necessary.

It depends on what kind of terrarium you’re building and how much organic turnover the system has to handle.

In a fully bioactive terrarium, where plant matter is constantly growing, shedding, and breaking down, the pairing makes the most sense. Larger debris accumulates (especially in the case of animal vivariums), and you need both species to tackle the problem effectively.

That said, in simpler, smaller, plant terrariums, springtails can often do the job alone.

You can always help them out by removing fallen leaves and such. In these setups, mold is usually the main issue worth managing.

Care requirements matter too. Springtails are largely self-sustaining once established, while isopods require more attention – feeding, ventilation, and population monitoring all become part of the equation.

The takeaway isn’t that every terrarium needs a highly-optimised cleanup crew, it’s that cleanup crews should match the workload of the system.

Most cleanup crew problems don’t come from choosing the “wrong” species (though sometimes that’s the case), they typically come from mismatched expectations.

1. Adding an Isopod Culture Too Early

A brand-new terrarium often doesn’t produce enough waste to support an isopod culture straight away. Even leaf litter provided for isopods needs time to decompose.

Without decaying matter, isopods are left competing for scarce resources.

This usually leads to populations stalling or crashing – not because conditions are bad, but because there simply isn’t enough work for them to do yet.

If you do want to add them right away (which makes sense, it’s the most convenient time) you can supplement their diet with food scraps or our Superfood Powder.

2. Expecting Springtails to Fix Moldy Terrariums

Springtails are much more effective at keeping mold in check than they are at tackling mold overgrowth.

If your terrarium is already looking like a spider’s web, it’s too big a task for a fresh culture of springtails…

Unlike isopods, I think there’s no problem adding springtails right away. There’s always a mold spore or thin biofilm developing somewhere for them to eat.

3. Overloading Small Terrariums

More organisms doesn’t mean better cleanup.

In small containers, adding too many isopods can lead to overgrazing, rapid waste buildup from the crew itself, and increased maintenance rather than less. Springtails are more forgiving at higher densities, but even they need limits.

Cleanup crews should scale with the volume and output of the system, not enthusiasm.

We recommend at least a 3-gallon terrarium container for one of our standard 10-count cultures.

This guide focuses on how cleanup crews function as a system. If you’re ready to look at species selection, care requirements, or population management in more detail, these guides break that down further:

• A deeper look at how different isopods behave and contribute in terrariums
• A focused guide on springtails in terrariums, including care, culturing, and mold control

Think of this page as the why behind the pairing – those guides cover the how once you’re ready to choose.