What most people don’t realise is that hydroponics is not a recent technique for growing plants.
Way back Before Christ, we find that the Arabs were growing melons on the dry and sandy riverbeds, being watered with solutions of composted animal excreta. A simliar process was used in India to grow watermelons, cucumbers and other green vegtables.
In China, into ancient times, rice cultures were carried in water, detailed in the diaries of Marco Polo.
One of the ancient Wonders of the World, the Hanging Gardens of Babylon were supposed to be grown hydroponically. There is talk of the plants being grown in channels simliar to the modern technique of NFT (Nutrient Film technique). The nutrient was recycled and transported back to the top in a bucket and chain system.