How Do Terrariums Recycle Air?

How is air recycled in a Terrarium?

• During the day plants take in sunlight, carbon dioxide and water and release oxygen, in a process called photosynthesis. They store the energy and food they create, and with nutrients from soil they function, grow and reproduce. Additionally, plants are always going through the process of respiration, like humans; they take in oxygen and release carbon dioxide. During the day, plants take in more carbon dioxide than oxygen, because sunlight is available and they can photosynthesize. At night, when there is no sunlight, plants take in more oxygen than carbon dioxide. In an airtight terrarium this process allows for enough carbon dioxide during the day for photosynthesis because it is replenished at night through respiration.

How do plants receive enough water?

• Terrariums can go a long period of time once constructed without needing water because, in the warmth of the day, water evaporates from the soil and plant leaves and collects as droplets of moisture on the glass walls of the terrarium. Eventually the water falls back to the soil and the process repeats itself. A properly balanced terrarium will have misting around the glass.

Materials for Creating a Terrarium

• Clear glass is recommended for creating a terrarium so maximum light can reach the plants, although terrariums can also be made out of household products like empty olive oil or wine bottles. The Toronto Botanical Garden's website recommends using a mix of three parts sterilized potting soil, two parts perlite or sand for drainage and one part peat moss or vermiculite to allow the soil to hold oxygen and moisture. When selecting plants for the terrarium, variety is important to make it interesting; think about different heights, shapes and colors. Be certain the plants are healthy and insect free with green, not yellowing, leaves. Sub-tropical plants will thrive best because terrariums are moist environments.

Brief History of the Terrarium

• In 1828, Dr. Nathanial Ward, a physician, was interested in watching an insect chrysalis to turn an insect. He placed the insect along with moss into a bottle. Ward noticed that condensation formed at the top of the bottle and circulated back to the mold in the evening. Eventually, he spotted a seedling in the bottle and decided to place the bottle outside his window. He did not intervene, and even without water, the plants inside the bottle survived and thrived for four years.