First, the substrate is flooded with a nutrient solution; then, the solution is drained. When the solution drains from the surface of the substrate, it is accompanied by ventilation, which brings fresh air to the root zone. Flooding systems are rarely used on an industrial scale, but they are very relevant for home hydroponic farming.
Using this method, the root system is well saturated with a nutrient solution. As a result, the plants develop rapidly and bring a bountiful harvest. But be careful: it is crucial to find the optimal irrigation cycle because it can differ depending on the season (even indoors!) and the size of the plants.