Hydroponics is a method of growing plants without soil. The plants with their roots are grown in an inert medium, provided with a nutrient solution or direcly in the solution.
Common media are perlite, gravel, rockwool or hydrocorrels. The substrate is suplied with nutrient solution either continually or in intervals.
A typical installation looks like this: The nutrient solution is pumped from a reservoir to a growing-tank or table by means of pump, tubes and drippers. The solution trickles continually through the substrate and the roots are sprinkled with it avoiding overfertilization, buildups and wasting.
In general hydroponics are designed for major undertakings but nowadays there are also some compact, handy and simple complete systems for easy and high-yield hydroponic indoor growing for everyone.
Some examples are presented here: