Clean Water Project
How to make your own Berkey filter container. Now that we have an official Berkey unit, and I see how simple it really is, we will be likely to take on this project. To test if the water is being filtered properly, Berkey recommends that you put a tsp of red food dye (it has to be red) into you full filter. If it comes out clean it is being filtered properly, if it's still red, then there's a problem.