Hydroponics is the art/science of growing plants in a soil-free environment. Historically, hydroponics isn't that new.In fact, there are many ancient records of people using the concept of hydroponics to grow plants.One such important record is the Hanging Gardens of Babylon, which is considered one of the Wonders of the Ancient World. In Babylon, they used gravel and stones to grow plants.While the system is certainly more primitive than what we can create now using our own two hands, it's important to note that the underlying principles remain the same.Throughout the last century, scientists and horticulturists experimented with different methods of hydroponics. One of the potential applications of hydroponics that drove research was growing fresh produce in non-arable areas of the world and areas with little to no soil. Hydroponics was used during World War II to supply troops stationed on non-arable islands in the Pacific with fresh produce grown in locally established hydroponic systems.Later in the century, hydroponics was integrated into the space program. As NASA considered the practicalities of locating a society on another planet or the Earth's moon, hydroponics easily fit into their sustainability plans. By the 1970s, it wasn't just scientists and analysts who were involved in hydroponics. Traditional farmers and eager hobbyists began to be attracted to the virtues of hydroponic growing. Hydroponic culture is soil-less, meaning, the soil has been completely eliminated from the equation. In place of soil, the grower uses a circulation system and hydroponic media to distribute water, nutrients, and air to the plants.A hydroponics system has two main parts: the grow beds and the reservoir.The reservoir contains the nutrient solution or the water mixed with various nutrients that plants need in order to grow successfully in the media bed. The grow beds, on the other hand, contain the media and the 'cups' that will hold the plants in place.To clarify, growth media will replace soil in a hydroponics setup. There are many kinds of growth media to choose from: coconut coir, perlite, organic-polymer composites, rockwool, etc.Among the beginning enthusiasts market, the most popular is coconut coir because it's 100% organic, expands tremendously with water and can accommodate plants easily - with spectacular results.