Detect lead in drinking water with a $0.45 filter cap

Author: Marya Lieberman

Directions and a video for use of the ND Filter Cap.

Filter Cap Showing Water Flow Small File
Soluble lead and lead particles are caught on the filter cap for easy analysis.

1). Collect 2L of water in a clean 2L soda bottle. 

2). Screw the filter cap on. Flip the bottle upside-down.

3). Use a thumbtack or safety pin to poke a hole in the bottom of the bottle. This will break the vacuum and let water flow out in a steady stream. 

4). It will take about 5 min to drain out. Don't squeeze the bottle or rest the cap on the bottom of the sink.  

5). Unscrew the filter cap and put it back into the zip-top baggie.