My original plan for this water filtration experiment was to do it for Earth Day, but things got too busy this year and we did something else instead (check out our posts for Homemade Seed Paper and Toilet Paper Roll Bird Feeders!)Today ended up being just the right day for it. I had the right materials on hand, we were headed to the pond for a pond study, and Daddy came home from work early which always makes field trips a little easier. So we put together our filter and headed to the pond wher