Springtails Are the Reason Your Terrarium Doesn't Turn Into a Mold Farm

Springtails are the smallest and most important thing you'll ever put in a terrarium. They're barely a millimetre long. They eat mold, fungus and decaying matter around the clock. And they are the entire reason a properly stocked bioactive build doesn't turn into a fuzzy white science experiment in its second week.

You will almost never see them. That's fine. That's them working.

Our cultures ship as an 8 oz container with an established, actively breeding population — mixed temperate and tropical species, so they perform across a wide range of conditions instead of one narrow band. Leaf litter and charcoal substrate included, ready to go straight in.

The two ways people kill them

Letting them dry out. This is the one they will not forgive. A dried-out culture crashes fast and does not come back — there's no reviving it, you start over. Keep them consistently damp.

Misting with chlorinated tap water. Chlorine kills springtails outright. Use dechlorinated, distilled, or rainwater. If your whole culture vanished for no apparent reason, this is almost always why — and it's the most common mistake I hear about.

Beyond that they're genuinely undemanding: 65–80°F, no light required, minimal ventilation, and a few grains of brewer's yeast or a pinch of rice weekly if you're keeping a standalone culture. In a planted terrarium they feed themselves on mold and decaying leaf litter and need nothing from you at all.

How to add them

Mist the tank first so the surface is damp when they land, then pour the entire culture in — springtails, substrate, charcoal and all. No sifting, no rinsing. Aim for the dampest area, on leaf litter or against a piece of wood. Never add them to a bone-dry build; if the substrate is dry, mist thoroughly and wait a day.

Then leave them alone. They vanish into the substrate immediately, and that's exactly what should happen.

How to know it worked

• Weeks 1–2: No visible sign at all, and mold may still be spreading. Don't panic and don't spray anything at it.
• Weeks 2–4: Mold stops advancing and starts receding. Mist the glass, look closely, and you'll catch tiny white specks moving in short hops.
• Month 2 on: Mold gone. Lift a piece of leaf litter and there's a scatter of white specks underneath. Established, and now permanent.

Keep a backup culture

Worth doing, because it means you never buy springtails twice. A small deli cup with charcoal or coco fiber kept permanently damp, a pinch of yeast weekly, lid on with a couple of pinholes, room temperature. Split it in half every few months — feed one half to your builds and keep the other going. That's the whole routine, and it takes about a minute a week.

One last thing: if you see springtails floating on the surface after a heavy misting, they're not drowning. They float on purpose. It's actually the easiest way to harvest them — flood the culture briefly and pour the floaters straight into your tank.