How Do I Raise the Humidity in a Tree Frog (or Frog) Tank?

By The Bognook Team · written & researched by amphibian keepers🔍 Keeper-reviewed for accuracy
A numbered how-to card titled 'How to hold your humidity', with five steps: know your target range (not 'as high as possible'); cover part of the lid to slow evaporation; keep the substrate damp but not soggy; add live plants and a water source; and keep some airflow. The point: hold humidity to the species' range with a gauge, rather than chasing maximum moisture.
Aim for your frog's humidity range, not the maximum. Put up a gauge, cover part of the lid, keep the substrate damp (not soggy), add live plants and water, and keep some airflow — steady and correct beats a swamp.

Low humidity is one of the most common frog-keeping frustrations — you mist, and twenty minutes later the gauge has crashed again. The good news: it’s almost always fixable, and usually the fix isn’t “mist more.” Here’s what actually works.

🐸 Not sure of your target? The free Tree Frog Planner gives you the exact temperature and humidity range for your species, so you know what you’re aiming for.

First: know your target

Humidity isn’t “as high as possible” — it’s species-specific, and some frogs dislike being too wet:

  • White’s tree frog: 50–70% (they actively dislike constant sogginess).
  • Red-eyed tree frog: 70–90%.
  • Poison dart frogs: 80–100%.

Aim for a stable range, not a swamp. And always pair humidity with some airflow — high humidity plus stagnant air breeds mould and bacteria. You want a fresh rainforest, not a stale one.

The fixes that actually work

Stack a few of these rather than relying on any one:

  1. Cover part of the lid. This is the big one. A full mesh/screen top lets moisture escape as fast as you add it — the #1 cause of a tank that won’t hold humidity. Cover part of it with glass, acrylic, or even foil and watch the gauge finally hold.
  2. Use a moisture-holding substrate. Coco fibre (kept lightly damp, not soggy) or a bioactive soil mix releases humidity slowly. Avoid dry, non-absorbent substrates.
  3. Increase the water surface. A larger, shallow water dish — or a bigger water area — gives more evaporation. Placing it near (not on) a gentle heat source raises output.
  4. Mist daily with dechlorinated or RO water, by hand or an automatic mister. Misting is a top-up, not the whole strategy.
  5. Add live plants. Pothos, philodendron, and ferns transpire moisture and hold it around the leaves (and look great).
  6. Mind the room. A very dry or air-conditioned room fights you — a partially covered, well-planted tank buffers against it.

The mistake to avoid

Don’t try to win with misting alone. Drowning a leaky, over-ventilated tank in water just gives you soggy substrate and skin problems for the frog. Fix the tank so it holds humidity — moisture-retaining substrate, more water surface, a partially covered lid, live plants — and then mist to top it up. Stable beats spiky.

Check it, don’t guess

Use a hygrometer (ideally a digital one, placed at frog height) so you’re tuning to real numbers, not hoping. Once the tank holds a steady range on its own, the daily routine gets much easier.

💚 If you’re battling the gauge every day, the answer usually isn’t more effort — it’s covering that screen top and letting a damp substrate and some plants do the work. Get the tank holding humidity on its own, and the rest is a light daily mist.

Go deeper: What humidity does my amphibian need? (all species, too dry vs too wet) · tree frog care basics · Is my tree frog sick? · the free Tree Frog Planner.

Common questions

How do I raise the humidity in a frog tank?

Combine several fixes: mist daily with dechlorinated water, use a moisture-holding substrate like coco fibre kept lightly damp, add a larger water surface, cover part of a mesh lid to trap moisture, and add live plants. The most common cause of stubbornly low humidity is too much ventilation — a fully screen top lets moisture escape as fast as you add it, so partially covering it usually makes the biggest difference.

What humidity does a tree frog need?

It depends on the species. White's tree frogs want a moderate 50 to 70% and actually dislike being kept too wet, while red-eyed tree frogs need a high 70 to 90%. Poison dart frogs need 80 to 100%. Always pair humidity with some airflow — high humidity plus stagnant air breeds mould and bacteria — and check the exact range for your species rather than assuming wetter is better.

Why won't my frog tank hold humidity?

The usual culprit is too much ventilation, especially a full mesh or screen top that lets moisture escape as fast as you mist. Other causes are a substrate that does not hold moisture, too little water surface, and a very dry room. Partially covering the screen (with glass, acrylic, or foil), switching to coco fibre, and adding a larger water dish usually solves it.

Should I just keep misting to raise humidity?

Misting helps, but do not rely on it alone — constant heavy misting to fight a leaky, over-ventilated tank leads to soggy substrate and skin problems. It is better to fix the tank so it holds humidity (moisture-retaining substrate, more water surface, partially covered lid, live plants) and then mist to top it up. Aim for a stable range, not a swamp.