What is needed in order to determine which is better for water permeability: water or clay?

In order to determine what is better for passing water: water or clay, first of all it is necessary to prepare all the components of the experiment. You also need to take two transparent containers, pour water into the first. In the second, you need to put a grid in the middle, and place clay on this grid, this is required so that the water has where to drain, since if the clay is at the bottom, we will not be able to evaluate the result. Then he pours water into containers in the same amount. Moreover, the water that we will pour into the water should be colored, otherwise the result will not be visible.