A well designed feed circuit will ensure all
roots are fed and flushed and not prone to blockages.
to make the feed circuit tidy and uncomplicated. To minimize the risk of
leaks and blockages avoid junctions and restrictive feed outlets (e.g.
drippers) and use filters (Fig 2.6).
Material selection (pipes and
Avoid metal because it is prone to corrosion.
Plastic components are generally cheaper, more flexible, readily available
and last longer.
Pipes: Flexible plastic tubing (e.g. polypropylene) is
usually appropriate for all situations and reduces the need for junctions.
Its cheapness provides the option of being discarded once it becomes
with other system components that contain nutrient, ensure the plastic is
black or opaque. This will help prevent the growth of algae on their
For junctions, push-fit fittings are
preferred (Fig 2.2). These are quick and easy to install. At high
pressures however, they are prone to leaks and therefore require securing
with clamps (Fig 2.3).
For the ‘primary’ circuit, rigid black (or
opaque) plastic pipes are preferable. These generally require glued
junctions. Note that rigid plastics are relatively brittle and therefore
inappropriate for high traffic areas.
Maximizing flow rate
- Pipe diameter: Use large diameter pipes. Do not
underestimate the degree to which small diameter pipes reduce flow rates,
especially as the length of the pipe increases. Small diameter pipes are
also more prone to
blockages from salt build-up, dirt, algae and plant
- Junctions: These also reduce flow rate and increase
the risk of blockages. In many situations junctions can be avoided by
using ‘flexible’ pipes instead of those that are ‘rigid’.