Appropriate grades or age groups:
elementary school

Estimated time to complete this project:
2-3 weeks

Materials:
salt, epsom salt, sugar, measuring cup, 3 glass bowls, 3 glass jars w/lids, use of stove, parental supervision

Instructions:
Make a supersaturated solution with the salt by boiling one cup of water then transferring hot water to one of the glass jars, then add salt and stir. Keep adding salt until no more salt can be absorbed by the water ... you will know this when instead of being absorbed, the salt begins to fall to the bottom. Repeat this with the others (epsom salt and sugar). Add a small amount from each jar to a bowl. Set the bowls in a quiet place and observe over the next 1-2 weeks. Close the jars and keep the solution for future use.

Other comments or suggestions:
This is a pretty simple experiment and my third grader really enjoyed making the crystals. There are many variations, but this one seemed the most simple and the one that she would be able to do by herself the most, with the exception of boiling the water and handling the hot water.