Step 5: Plant solution
With the tube clamped to the top edge of the tray, add enough of your chosen plant solution from your pitcher to cover the growth media.
The solution will not drain when the tube is clamped above the tray top.
After your pitcher is emptied or the tray is filled, drain the excess solution by unclamping your tube and placing it into your pitcher that you have now placed below tray level so that your hydroponic setup may drain by gravity.
Repeat as necessary.