G
rowing plants in an aeroponic
system is simple if certain environmental parameters are met. For
example, if your water temperature
never reaches above 64°F, bad biology
and enemies of aeroponics such as
algae and root rot can hardly begin to
grow, much less thrive.
Maintaining your water temperatures
below 64°F requires keeping ambient
room temperatures below 72°F, and
this can be quite a challenge, especially
in the summertime. A water chiller
may be necessary to keep the reservoir
cool. You may also need to invest in air
conditioning or more efficient lighting to shield the root chamber from
the heat caused by some grow lights.
Many unseasoned aeroponic growers
overlook these steps and accidentally
allow their roots to cook in between
spray cycles. They eventually notice
the plants are struggling with early
stages of roots that have likely contracted water molds such as pythium
or phytophthora. These problems are
also commonly found in hydroponic
systems when water temperatures are
not kept at reasonable levels. However,
because aeroponic roots are dangling
in the air with no medium to provide
an advantageous microclimate where
evaporative cooling can occur, aeroponic systems are much more susceptible to pathogen problems. It’s time
for some troubleshooting.
Troubleshooting
If plants begin to slow down in growth
and vigor, this is the first sign you need
to pay closer attention to what’s going
on. When plants look like they are suffering, there is likely a problem with
the environment, pathogens or pests.
Take a look at your growing environment first. What are your temperature and humidity levels? Are these
parameters providing plants with the
“
When plants look like they are
suffering, there is likely a problem
with the environment, pathogens
or pests.”
environment they need to grow? What
works with soil, soilless or hydroponic
gardening may not work as well with
aeroponics since roots are exposed
and hanging in the air. The growth
chamber is under a light and can be
heated up even more than the surrounding air. For this reason, reservoir
temperatures must be kept lower so
the water can cool the roots when they
are sprayed. Roots are typically misted
every 1-4 minutes so they can be kept at
the proper temperature by the cooler
water in the reservoir.
Spraying roots with an aeroponic
system will help avoid root aphids,
fungus gnats and so on from laying
eggs on the roots in the mist pattern,
but aeroponics does not completely
prevent these types of pests. They
will still find ways to reproduce in an
aeroponic system by finding areas to lay
their eggs that are safe from the spray.
Be on the lookout for common growroom problems, but keep a close eye
on the roots. They need to be healthy
and thriving at all times to maximize
the benefits offered from aeroponics.
Discoloration can occur when using
certain nutrients that are slightly tinted,
such as humic or fulvic acids and organically mixed nutrients. For this reason,
color is not a reliable indicator of root
health and vigor. Observe the ends of
the roots to verify they are healthy and
growing new tips. In addition to browning, rotting roots will develop a slimy
coating and immediately lose their vigor.
Clogged nozzles are perhaps the
most common problem associated
with aeroponics. Fortunately, they are
completely avoidable. Clogged nozzles
result from the infrequent cleaning
of filters, pumps, tubes and fittings.
Another common culprit is allowing
the system to dry out after harvesting
and before cleanup, which leads to
nutrient salts accumulating on the
inside of the plumbing. When the
system is turned on again, these salts
break apart and the solids can easily
block the nozzle’s orifice. Likewise,
nozzles will often clog before harvest
time if the filter is not kept clean.
Clean the filter in between sprayings,
or temporarily power off the pump,
leaving the filter assembly submerged
to prevent air from entering the lines.
Maintaining a Healthy System
Maintaining a healthy aeroponic system
can be achieved by keeping a sterile
reservoir and grow system, or by inoculating and maintaining a population
of beneficial biology into the reservoir
and grow system. Both of these methods will maintain a healthy system even
though they are virtually opposite from
one another. In a sterile system, growers use hydrogen peroxide, enzymes
or other similar products with their
nutrient mix or in between feedings to
keep things clean. On the other end of
the spectrum is the inoculation of good
biology to prevent the bad biology from
Maximum Yield USA | June 2016
153