Group #2: Ms. Luisa had E. B. put a chemical in the dirty water called alum, and it made the dirt in the dirty water get together like magnets sometimes do. She helped us understand how this works by having a bunch of us pretend to "not like" each other and then, after we had alum put on us, we did a big group hug. We also learned that when things come together like this, it's called "coagulation". So, once the dirty water gets in together in balls, it falls to the bottom of a container and then it's easier for the cleaner water to be poured off from the top. N.R. said, "It was my mom that did this (presentation), and I felt proud of her because she did such a good job!"
Group #3: Later E.P. put dirty water in a filter that had sand on top of small rocks, and it let water come out of the bottom. When E.P. put the dirty water in the the top of the filter, it went through the sand and came out as CLEAN water! But it wasn't so clean, because there could still be some germs inside of it. So then we put in another chemical to clean the water, and it was called "chlorine". Still we didn't drink this really clean water, just in case. There could have been "jiaryas" (Giardia)!