Today I set up and tested a flood and drain system for a growing project. It has been sometime since I have used these systems, so I had to do a complete setup and test.
The grid and screen on the bottom are intended to prevent the roots from laying in standing water. The grid is from Home Depot, and is used to defuse lighting. It is inexpensive and can easily be cut to size.
The beet green seedlings had grown to the perfect size for planting, so I decided to plant them before they got much larger.
The photo below shows a seedling after being placed in the system. As you can see I have buried as much of the stem as possible to provide support to the tiny seedling.
When I placed the plants into the flood and drain system, I filled all of the space around the pots with expanded clay pellets. The photo below shows the system while being flooded. The extra layers of pellets keep the top dry, which prevents algae from forming, thus eliminating the possibility of fungus gnats.