You don't always need a fancy hydroponic system for your class to learn. Sometimes they can just make their own. Ledford FFA students learned the basic principles of hydroponic growth and then applied their knowledge by making their own units.
But isn't a complete system better?
Yes, it can be but it depends on what your intentions are. If you don't have a facility or a budget to house and maintain a fully functioning setup then a DIY version that your students create is right up your alley. The set up that Ledford FFA uses is pretty basic but suits the students well.
If you can look at the picture close enough you see the that the containers are sports drink and soda bottles. They cut the neck off the top and flipped it over. A small hole was drilled through the cap and a small piece of twine or yard is threaded through the hole into the base of the container where the water is held.
A cube of rock or mineral wool is placed in the space left by the bottle neck and with that you now have your own hydroponic growing unit. Now just place seeds in the rock wool and ensure that it remains moist and under appropriate light as seen in the photo. To limit the units drying out, try and locate a spot where there are minimal drafts and the humidity around the units remains high.
If you are looking for other ways to propagate plants then look at Vegetable Propagation in Plant Science and see if this DIY activity fits your class. We also have some great Plant Science lesson plans on our website. Click over and find one that works for you.