How to construct a biodome (closed ecosystem) for classroom use
Before the Activity
In constructing these, you create a device that has an endless number of uses. I now use a standard ten gallon aquarium (though I still have a 5 gallon that was the prototype) that I top with a close fitting piece of plexiglass.
Before attaching the plexiglass, I cut a couple of holes in it to accommodate a stopper with a hole big enough for a temperature probe. I also cut a hole big enough to accommodate one of the CO2/O2 Tees purchased from Vernier.
The third hole is big enough to accommodate the top of a plastic 1 gallon jar (I get these from our cafeteria, they get them with pickles and banana peppers in them). I cut the jar about an inch below where the tapering from the top of the jar ends and levels out down the side of the jar. The tee and jar lid will need to be sealed on both sides with an epoxy type glue ( I use a product called liquid welder).
Once this dries, the plexiglass can then be sealed to the top of the aquarium. You will also need to seal around the top plastic piece inside the aquarium. Leave the lid off of the jar to allow adequate ventilation for the sealant to dry.
NOTE: This activity does not contain attachments.
During the Activity
Once finished, you have an opening in which materials can be added or removed and an environment that can be sealed. If you are not using the CO2 sensors or the O2 sensors, these holes can be plugged using a stopper. In class these have been used for many things including student designed investigations into various photosynthesis and respiration experiments.
After the Activity
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary