Hydroponic
units contain every component to successfully grow a plant without soil.
The necessary components are a tray with channels for the plants to
grow on. Sometimes an inert grow medium is used, such as expanded clay
pebbles. This allows for the roots of a plant to grab onto something,
but still allows for plenty of air and drainage, but exposes the roots
to the solution.
Another key piece to a hydroponic unit is the pump. It should be powerful
enough to allow the solution to flow at the desired level and speed,
but efficient enough to be turned on 24/7. Constant solution flow is
necessary for hydroponic systems to work effectively. The nutrient solution
is the next step and often the mix is included with the unit, adding
water is the only necessary step, but replacements should be purchased
as well.
For indoor use, hydroponic units often contain lights as well. Since
power is already being routed through the system, the pump is often
integrated into the power supply allowing for only one plug to operate
the entire system. These can be used anywhere, even underground, because
sunlight is no longer needed. This allows for constant food supplies
even in winter or areas with complete darkness.