The Internet has greatly helped to disseminate useful, up-to-date information about successful hydroponics techniques to anyone with a computer and an Internet connection. A few aspects have emerged as being "the cutting edge" of advanced hydroponics. These include the "aeroponics" growing technique; integrating wastewater, or "gray water," into the hydroponics system as a means of treatment and reuse; and ambitious new designs for urban hydroponics farms to alleviate future food-production crises as the world's population increases.
The principles of hydroponics were first defined by Sir Francis Bacon in the 17th century. The 1930s, research by professor William Frederick Gericke of the University of California at Berkeley resulted in what we know today as the modern science of hydroponics. Gericke's 1940 book, "Complete Guide to Soilless Gardening," is considered a watershed in the field. Today, hydroponically grown produce and ornamentals are commonplace in the commercial markets as well as in home gardens.
The National Aeronautics and Space administration (NASA) has performed extensive research into hydroponics techniques to better understand how astronauts would provide food for themselves on long space flights in a research effort called the Controlled Ecological Life Support System (CELSS).
Different hydroponics methods each have their own slightly different way of accomplishing the same goals: delivering both nutrients and oxygen in optimum proportions for use by a plant's root system. These techniques include the nutrient film technique (NFT), flood and drain, the floating raft technique, drip systems and aeroponics. Of all these types of hydroponics setups, aeroponics has emerged as especially useful in long-term spaceflight scenarios where the availability of water is at a premium. With aeroponics, only a regular misting of nutrient solution on the root systems of the plants is needed--no huge reservoirs are necessary.
Advanced hydroponics will integrate food production and wastewater reuse for terrestrial and space applications. There are many benefits to incorporating plant production with gray water treatment. NASA is exploring "biological gray water treatment (by nitrification and denitrification) followed by a physiochemical process such as reverse osmosis, ion exchange or UV oxidation to treat and reuse graywater" produced by astronauts on long space flights.
According to Mother Earth News, statistics show that the human population will keep on increasing, eventually adding another 3 billion people to the planet, and conventional farming practices will not be able to produce enough food for everyone. Fortunately, the high crop production rates resulting from "vertical farming" via hydroponics will solve the problem. Vertical farming includes techniques such as using old, abandoned buildings for hydroponics farms, stacking multiple levels of hydroponics growing tables for efficient use of space. Artificial lighting will be used to provide for sufficient photosynthesis to take place. Using these techniques, hydroponics can be approximately 30 times more efficient per unit area of land than soil-based farming.
According to Steven Carruthers, managing editor of "Practical Hydroponics & Greenhouses" magazine, another promising hydroponics-based farming technique is aquaponics: the combination of aquaculture (fish farming) and hydroponics. In aquaponics, the waste water from a fresh-water aquaculture operation is used to provide organic nutrients for the hydroponics operation. This process helps to act as a sort of natural filter for the waste water so it can be recirculated to the aquaculture operation or discharged with only minimal pretreatment. The advantage is a significant reduction or elimination of plant nutrient costs. The trade-off is that maintaining the proper balance in water quality for the dual-purpose uses is a constant juggling act.