049ISSUE 32OFFGRIDWEB.COMHYDROPONICS
BASICScan work in a home system, with an ideal slope of a half-
inch drop every 15 feet.
Because the nutrient is recirculated, water quality can
become a concern, and it’s usually necessary to com-
pletely change the solution periodically.
Float systems are another type of hydroponics that
are relatively simple for a home grower to grasp. In these,
rafts made of Styrofoam hold the plants and float directly
on the nutrient solution. Since there’s no air space be-
tween the solution and the raft, some type of bubbler is
needed in the reservoir to supply oxygen to the roots.
This system is often used by tobacco farmers to start their
transplants, and many of these systems have been adapted
over the past decade to start other transplants, such as
tomatoes, pepper, and even corn. The transplants that are
started hydroponically are then grown in natural soil.
In the aeration method, the nutrient solution is misted
onto the roots, often from within an A-framed Styrofoam
structure into which the plants are placed. Excess solution
runs back into a reservoir and is recycled.
Yet another style of hydroponics is bag culture, where
plants are grown in polyethylene bags filled with a medi-
um-like vermiculite or peat. Capillary tubes that run from
a main nutrient supply line are inserted into each bag,
delivering the nutrients. (In one university demonstration,
bag culture tomato plants grew so heavy that they dam-
aged the steel frame of the greenhouse to which they
were trellised!)
Top left: Crops
grown hydro -
ponically are
physiologically
no different than
crops grown in
soil.Top right: To-
bacco transplants
begun in float
beds.Bottom left:
The nutrient
film technique
recirculates the
nutrient solution
so that roots sit in
a constant flow.