Hydroponics is a gardening technique that uses water instead of dirt to grow plants. The advantage to this system should be immediately obvious. Hydroponic systems do not use dirt; therefore, it can be set up anywhere.
This versatility has many advantages. For those living in apartments or areas where space is limited, a hydroponic setup will allow a small crop to be grown and harvested just about anywhere. In a spare bedroom, on the balcony, or even on the roof of the building are all acceptable places to set up a hydroponic system.
Hydroponic systems take up much less space allowing you to plant more in the same space than you would with a conventional dirt medium. This is because the nutrient rich water is brought directly to the root systems of the plants. The roots will not have to continue growing in search of nutrients so they remain small. Plants will not be fighting for nutrient rich soil and overall the crops tend to be much healthier.