The modern definition is that hydroponics is
the growing of plants without soil. When you
grow a plant hydroponically, all the nutrients
and all the water is readily available to the
plant (traditional potting mixes only release
about 70%). Thus in hydroponic the plant does
not have to work hard to get the food and water.
It can therefore spend all it's energy on growing
the plant instead of growing roots. In soil
the big root net is necessary for the plant
to be able to find enough food and water.
not Soil, Then What?
Typically, there are several types of growing
media for hydroponic systems. These
are all coarser than soil so that there are
air/water pockets between the granules that
allow the plant's root system to breathe better
(gives the root systems better access to oxygen,
which is essential). These growing media
Coir (shredded Coconut husks, common trade
names are Ultrapeat, Cocopeat, Coco-tek)
(air puffed glass pellets)
(Lightweight Expanded Clay Aggregate)