The right light is essential for the health of your plants.
There are two simple rules to prevent your plant from getting too little light and starting to mold, or too much light that could cause the plants to burn. Think especially of direct sunlight.
Place your terrarium close to a window, but make sure that no direct sunlight can fall on it. North-facing windows often provide too little light.
Turn your terrarium a quarter turn every 2 week. This way the plants get even and sufficient light.
A closed terrarium creates a humid climate itself so that the plants keep themselves alive.
The plants perspire water in the form of vapor, which partially condenses, so that droplets become visible on the inside of the glass. These drops moisturize the soil and ensure a moist environment in which the plants thrive.
Sometimes there is too much condensation: your plants are hardly visible anymore, open the pot 10 for 15 minutes. This way the excess moisture can evaporate. This is always a result of a plant that has too much heat, usually due to sunlight.
Take the soil as a guide for how moist it is in the pot. If the soil feels dry then it is time to water it. This will occur less frequently with a closed terrarium, once every six months.
It doesn't need much water; such an 50 to 100 milliliters, depending on the size of the terrarium.
The terrariums should be kept indoors and the best temperature is between 16 and 27 degrees.
If it is warmer than 27 degrees, open the pot briefly and give some water if necessary.