Ta Do: Hands… on Science Season 1, Episode 5 – Water Filter Send us your comment! https://midnightscienceclub.com/paren… Make your very own water filter! Materials: 1 – 2 liter bottle, w/hole on cap Scissors, or box-cutter 6 coffee filters 1 cup of gravel Bag of activated charcoal (rinse it w/water once) 1 cheese cloth How to do it: Cut the top part of the bottle, and place top part upside down in the bottom part of bottle. Place 1 coffee filter, then pour in the activated charcoal, and place a coffee filter on top of it. Take one cheese cloth, loosely fold it and place in the coffee filter, then place coffee filter on top of it. Finally, place the gravel on the coffee filter. Pour “dirty” water through the filter, and watch it filter the water. You may need to filter it through couple of times to have it run clear.