27/08/2026
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*Understanding Condensation in Your Bottle Garden*
🌿 Don't judge the health of your terrarium by the amount of condensation on the glass.
My own Biki Knysna terrariums live under grow lights and often have very little visible condensation — yet they are exceptionally healthy and growing beautifully.
What matters is the balance of the entire ecosystem, not how wet the glass looks. Water is constantly moving through the little forest: from the soil, into the plants, into the air and back again.
Sometimes the healthiest terrarium is the one that doesn't look wet at all. 💚
You may also notice that your bottle garden produces more condensation when it is outside in natural light than when it is indoors.
Condensation is not a measure of whether your terrarium has enough water. It is simply part of the natural water cycle and is affected by temperature, humidity and the environment around your bottle.
💧 Why does condensation appear?
Your plants take up water from the soil and release some of it into the air through transpiration. This creates water vapour inside your closed bottle.
When the humid air meets cooler glass, the invisible water vapour turns into tiny droplets — condensation.
Outside, natural humidity and the changing temperatures between day and night can make this process much more noticeable.
Indoors (with or without a grow light), the bottle and glass may remain warmer and therefore hold more water vapour without producing visible droplets.
🌱 So, should you be worried if your glass is clear?
No!
Don't water your terrarium simply because you don't see condensation.
Instead, look at the whole little ecosystem:
🌿 Are your plants growing and looking healthy?
🌱 Is the moss green and hydrated?
💧 Is the soil slightly damp rather than bone dry?
🍃 Does everything look fresh and alive?
If the answer is yes, your terrarium is probably doing exactly what it should.
Likewise, lots of condensation isn't necessarily better. Constantly dripping-wet glass can indicate that the ecosystem is holding too much moisture.
🔍 Become a Forest Explorer!
Rather than looking for a particular amount of condensation, observe your bottle garden over time.
Notice what happens in the morning, during the day and at night. Watch how the plants, moss, moisture and tiny creatures interact.
“A healthy terrarium doesn't have to look wet. Sometimes the most important water is the water you cannot see.” 🌿💧
Your bottle garden is a living ecosystem — and every day it has something new to teach you.
*Biki Knysna Bottle Gardens*
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