There are two types of systems, the flood and drain table system and the modular or bucket flood and drain system. With the first, the plant is resting above the nutrient solution reservoir- this looks like a flat table- which is where the name comes from. The table is designed to drain the solutions into the center of the plateau towards the inlet, a pump connects the inlet with the overflow drain which is funnelled back into the reservoir. If the pump is turned off, the solution then flows back down the inlet drain into the reservoir.
This pump is controlled with a timer that allows you to set how often the intervals are for the flood and drain table system. Flooding provides the nutrients the plants need and allows you to grow in any medium such as soil or clay pebbles. In comparison to other hydro setups, this is a leak-proof method- especially helpful for urban or, say, apartment growing. The flood and drain table system will perfectly fit the typical sized greenhouse or grow tent.
With the second flood table system, the modular and bucket flood and drain system, an essential difference is that each plant is sitting in its’ own pot and not on a table for flooding. Each of these pots has a supply tube that is attached to it leading from the lower part of the pot into the control bucket which is connected to the nutrient reservoir.
A bucket-based flood and drain systems pump is simply draining and flooding the control bucket. The solution is then given to the connected plant pots via gravity. This control pot utilizes magnetic valves that run the pump and flood level, which prevents flooding or over-watering.