Place your terrarium in a bright area with indirect sunlight, (ex. windowsill, well-lit workstations). These terrariums are a closed system; it can get too hot if placed near a direct heat source and the plants may burn.
Water – A properly maintained terrarium can go for weeks or months without needing water. Checking for condensation is the key. If the sides are never condensing, pour a half glass of water. If there is too much condensation that you cannot see your plants, then open the top of the container temporarily to allow it to dry.