off and is wasted. Short run cycles also assure that watering
stops when the entire growing medium has been moistened.
Different growing mediums, as well as growing conditions,
will greatly affect the time between waterings for your drainto-waste system. Take rockwool for instance; when watered,
it will typically hold a ration of about 80% water to 20% air
(remember that plants need oxygen in their roots just like they
need moisture). Depending on plant transpiration and evaporation, this medium will go about 24 hours between waterings.
Alternatively, utilizing multiple short waterings throughout the
day will allow the growing medium to have sufficient drying
time before the next watering cycle while keeping the medium
moist enough for optimum plant health. Either way, alternating
the moisture level between wet and barely moist will result in
better plant health and greater yields.
As mentioned earlier, each growing medium has different
water retention characteristics. Also, remember that an increase
in transpiration is normal as your crop matures, which causes
higher water demand. (Higher ambient air temperature will
also increase transpiration.) Once you know you’re plants’ and
growing medium’s characteristics, you will to need dial your
drain-to-waste system into the ideal watering cycle. This means
you’ll need a quality timer with run time and cycle versatility.
There are many different types of hydroponic systems, and
what basically divides these into two categories is whether the
water is recirculated or drained off to waste. No matter which
of these you choose for your crop, be watchful off the common issues specific to each system and deal with them accordingly. Also take notes and do your research so that it gets easier
for you with each new crop. Agriculture and horticulture are
sciences; treat your crop
this way and you will make
success common. MY
“Alternating the
moisture level
between wet and
barely moist will
result in better
plant health and
greater yields.”
Maximum Yield USA | September 2012
131