Fig. 1

Glass Bead semi-hydroponic system. a Glass tube. b Drain glass tube connected to 3 cm Viton tubing and closed with an acetal clamp. c Top of the glass tube filled with glass beads covered with a Teflon lid. d Details of the Teflon lid showing the four perforations. e “Y connector” attached to 4 cm Teflon tubing and sealed with Teflon tape. f “Y connector” inserted in the Teflon lid, showing the diagonal angle to water the plants. g Germinated seeds placed on top of the glass beads. h Planted seeds covered by the Teflon lid after planting. i Glass tube with planted seeds covered by glass beads and with the “Y connector” inserted. j Plants growing in the glass tubes in a growth chamber (1. Rack tubes, 2. Viton line, 3. Glass carboy containing Hoagland solution for watering plants. 4. Peristaltic pump). k Details of the watering system (5. Branched pipe 2 × 8, 6. Outlet lines inserted in the “Y connectors”). l Details of the branched pipe (7. 3-way connector, 8. Barbed adaptor, 9. Compression fittings, 10. Teflon tubing connecting the compression fittings)