Filtration at Work*

At Home with + POOL

Estimated Time: 30 minutes

Subjects: Science

Grade: K-5

What You Need At Home: pitcher or large container, “pollution” materials, coffee filter, piece of thin cloth or rag, a strainer, six cups, rubber bands

Activity: Build your own filters

1. Fill up a pitcher with clean water right from the tap.
2. Gather your “pollution” materials — you can use dirt, coffee grinds, egg shells, cat litter, and/or vegetable oil.
3. Invite your kids to “pollute” the water in the pitcher with all the items you’ve collected.  This is your chance to talk about pollution. What it is, what it does, and why its yuckie. 
4. Grab your six cups and build two of each of your filters: take the following materials and place one over each cup with a rubber band to affix it to the cup. 
   1. A coffee filter 
   2. Piece of thin cloth or rag 
   3. A colander or strainer with some rocks or dried beans
5. Ask your students to write a hypotheses:
   1. Which filter do you think will keep out the most gunk?
   2. Which filter do you think will be fastest?
   3. Why do you think that?
6. Try them out! Pour the contaminated water through each filter and observe which cleaned out the most oil and junk.
7. Observe and report. How did the results compare to your hypotheses?
8. Now try using each separate filter as a full comprehensive system.
   1. Pour the contaminated through the colander filter first
   2. take the colander filtered water and pour it through the strainer
   3. take the colander filter & strainer filtered water and pour it through the coffee filter

 …how did the filtration system work? Let us know @pluspoolny!

Note: Depending on which materials you gather from your home, each “filter” should react to various materials a bit differently.  Oil will likely go right through the paper and the colander, but will be captured by the cloth. The egg shells will be captured by the colander, but may pierce through the paper. Explain how using  a combination of various filters, + POOL will filter NYC’s river water for swimming!

Download the full curriculum.