Flood and drain table exhaust system
My 4'x3' Flood and drain table is covered with a lid that has holes in it to house 5" pots full of hydroton and a plant.
The cover protects the roots from the light and helps to keep the algae down. The cover, being white helps to reflect light back up to the lower leaves. The down side to the cover is it restricts fresh air from getting to the root area.
To help correct this issue I decided to take a computer fan and make up an adapter to allow the fan to be mounted to the cover. The fan exhausts air out from below the cover.
New air can enter via the small openings around the pots, the cover where it meets the table and down through the hydropton from the top of the pots.
i just put it together today, so it will be interesting to see what effect it has on the plants health and growth.