Learning Objectives

By the end of this lesson, learners will be able to:

• Identify the main microfauna species used in bioactive vivariums.
• Understand how microfauna process waste and recycle nutrients.
• Explain why microfauna populations need time to stabilise.
• Recognise signs of a healthy vs. unhealthy microfauna colony.
• Understand how microfauna interact with substrate, leaf litter, and environmental conditions.

Lesson Content

Microfauna are the foundation of every successful bioactive vivarium. These tiny invertebrates—primarily springtails, isopods, and beneficial microscopic organisms—perform a crucial function:
they prevent waste from accumulating and keep the vivarium clean without manual intervention.

In the wild, dart frogs live among dense layers of decomposing leaves and fallen plant matter. Microfauna constantly break this material down, recycling nutrients back into the soil. A bioactive vivarium mimics this natural process on a smaller scale.

1. What Microfauna Are and What They Do

Springtails (Collembola)

• Small, white, soft-bodied insects
• Thrive in moist environments
• Feed on mould, fungi, and decaying organic matter
• Help prevent mould outbreaks in new or humid tanks
• Reproduce quickly and stabilise early

Springtails are your first line of defence against mould and fungal growth.

Isopods (Woodlice / Pill Bugs)

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They:

• Break down leaf litter
• Consume faeces and uneaten food
• Aerate the top layer of substrate
• Add nutrients back into the soil
• Provide a sustainable cleanup workforce

Dart frogs occasionally eat very small isopods, but healthy colonies replenish themselves faster than frogs consume them.

Beneficial Microbes

These include bacteria and fungal networks that:

• help break down waste
• stabilise substrate chemistry
• create long-term soil health

They are not purchased—they form naturally as the vivarium matures.

2. How Microfauna Maintain a Clean Vivarium

When a frog produces waste or a plant drops a leaf, that material enters a natural decomposition cycle:

1. Springtails begin feeding on fungal growth.
2. Isopods shred larger debris and consume faeces.
3. Microbes break down leftover waste into nutrients.
4. Plants absorb the nutrients through their roots.

This cycle repeats continuously, just like in a forest floor ecosystem.

The result is a cleaner, more stable vivarium without regular substrate changes.

3. Establishing a Microfauna Colony

Initial Introduction

Microfauna should be added before frogs whenever possible.
A typical timeline:

• Week 0: Add springtails and isopods.
• Week 1–2: Springtail population grows; isopods settle.
• Week 3–6: Visible activity increases; leaf litter begins to break down.
• Week 6–12: Colony becomes self-sustaining.

You can add frogs earlier, but full bioactive performance comes once populations stabilise.

4. Signs of a Healthy Microfauna Community

A thriving microfauna colony looks like this:

• Isopods are found under bark, cork, and leaf litter.
• Springtails are visible when the substrate is disturbed.
• Leaf litter slowly decomposes over weeks/months.
• No strong odours are present.
• Mould appears but disappears as springtails consume it.
• Plants grow steadily.

5. Signs of an Unhealthy or Collapsing Colony

Problems arise when environmental conditions are off:

• Very slow or stunted isopod reproduction
• Large mould blooms that don’t reduce
• Foul smells (often due to anaerobic substrate)
• Mushy, oversaturated substrate layers
• Dry leaf litter and collapsed moisture gradients

These issues usually point to:

• insufficient humidity
• substrate too wet or too dry
• low ventilation
• incorrect lighting
• lack of initial microfauna seeding

This is why stability in Module 1 is so important.

6. Boosting and Maintaining Microfauna

To support microfauna:

• Add fresh leaf litter every 4–8 weeks.
• Keep humidity consistent.
• Avoid chemical cleaners.
• Spot-feed isopods with small amounts of:
  • Repashy Morning Wood
  • Fish flakes
  • Dried seaweed
• Add additional springtail cultures every few months if needed.

A strong microfauna population equals a healthy bioactive vivarium.

Key Takeaways

• Microfauna are essential for breaking down waste and preventing bacterial buildup.
• Springtails handle mould and fine decomposition.
• Isopods process larger waste and leaf litter.
• A balanced microfauna population creates a stable, self-cleaning environment.
• Tank maturity depends heavily on microfauna density and health.
• Poor colony health is usually caused by environmental inconsistencies.