Although it sounds complicated, growing plants hydroponically requires very few supplies. Obviously there is no need to work the soil or pull weeds, but plant roots need oxygen as well as nutrients to grow healthy and produce a crop. The supplies needed for hydroponics are few and, with the exception of the nutrient solution, reusable as long as you practice good sanitation after harvesting one crop and before planting another crop.
Hydroponic plants grow without soil in a water-based nutrient solution and need to be grown in watertight containers. The containers should also have a lid. Large holes are drilled into the lid and plant sleeves or net pots are inserted into the holes. Net pots are rigid pots with a series of holes or nets in their sides to help the nutrient solution more easily reach the roots. The plants are planted in growing medium in the sleeves or net pots and the roots are held in the nutrient solution while the tops grow above the lid of the container.
A soilless growing medium is used both to support the top growth and roots of the plants. Rock wool is commonly used. It is a man-made mineral fiber made by melting a basaltic rock. The melted material is then spun into fibers. A binder is then added and the mixture is compressed into large slabs, according to Oklahoma State University Extension. Other mediums commonly used are peat moss, pine bark, gravel, sand, vermiculite or perlite. These are more commonly used as soil amendments in traditional garden or container growing to lighten the soil, provide air pockets to facilitate drainage and hold moisture. Because they are sterile, they are ideal for hydroponics as they contain no disease organisms that can infect hydroponically grown plants.
To aerate the nutrient solution and provide needed oxygen to the plants' roots, a circulating pump is needed for hydroponics. For a small system consisting of a single large container planted with a dozen or so plants, an aquarium-type aerator pump is adequate. For larger systems encompassing an entire greenhouse, a larger pump is needed. For this application, special circulating pumps made specifically for hydroponic growing are available.
Plants grown hydroponically derive all of their nutrients from the solution in which their roots are immersed. Special nutrient solutions specifically for hydroponics are needed to ensure the plants get the nutrients they need to grow healthy and produce a crop. They contain the big three plant nutrients--nitrogen, phosphorus and potassium--along with trace elements found in soil and that are necessary for plant development and to produce crops.