We were reviewing the water cycle in earth science and talking about evaporation and condensation. This experiment is to see how dirty undrinkable water becomes something people can use.
Our supplies are a large bowl, small bowl, cling wrap, water, dirt and food coloring. First add a couple of inches of water to the large bowl.
some red food coloring...
and some blue food coloring. That is to make purple because Dancer always like purple in her experiments whenever possible.
Place the small bowl in the center of the big bowl dirt water pond.
Cover the large bowl with the plastic wrap. Add a weight on top of the center of the plastic so that condensation will run "downhill" to the middle and collect in the small bowl. Put the bowl out in the sun so you get a lot of evaporation. The water that we collected was crystal clear.
Water that comes to us as rain, snow, fog or dew is clear and pure. Most of the water which we receive as condensation is evaporated from the oceans. Thankfully our rain isn't salty. Evaporation and condensation is how water from a stinky old swamp or polluted ditch gets recycled so people, animals and plants can use it.
Bonus lame joke:
Q: What did the scientist ride to the beach?
A: The water cycle, of course