Mary from New Mexico made the following, very good additions to our latest Earthlearningidea 'Water, water everywhere but not a drop to drink' -
"I often use this as a 'challenge' activity, where student teams compete to see who 'best' cleans the water. I offer the students a choice of possible items to filter and let them design their own filters using different layers. The biggest challenge is getting the blue food coloring out of the water. This exercise really works well with the cut off bottles as funnels. If you have a microscope, students can easily see some of the small organisms in the water and you can incubate your own by putting grass clippings in water and letting it sit."
These are positive and enhancing comments which we have published in our 'Extension Ideas'. Thank you Mary!
We shall be very pleased to receive any other suggestions to add to these to take the investigation further.