Within the trays are placed pieces of foam that are about 7 inches square. The foam is raised off the bottom of the tray with 5 decking screws (not shown). Raising the foam prevents floating and provides a larger reservoir in the tray. A cloth covers the foam and the edges extend down into the water below. This serves as a capillary mat. The pots and trays with the seeds and plants are placed on top of the mat. If the holes in the bottom of the containers are not conducive to moving the water from the mat to the soil,a small wick or two (made from a paper towel) is placed in holes in the bottom of the container |