A hand pump was added to the water filtration system. The children squeeze the pump over and over again to suck the water up the tube and into the top layer of rocks. Any dirt left in the water is sucked up the tube with the water and goes through the filters again and again.
It takes practice to get the rhythm of squeezing the hand pump to get the water going.
The children realize they have to work together.
Someone holds the tube so the end of it stays under the water. Trial and error is a great teacher!
The water is becoming cleaner and cleaner.
Children use different methods of recirculating the water.
Why is the water still dirty after it gets filtered?
Does the water look cleaner when it comes out of the tube?
We're going to get that water really clean. We'll pump it in again!
Everybody takes turns pumping the water, holding the tube and watching to see if the water is coming out into the rocks.