hydro nutrients
A couple teaspoons of three per cent hydrogen peroxide per
gallon of water in your system can be a great nutrient addition
for a deep water system. This extra oxygen will help the roots
better absorb nutrients and reduce the spread and growth of
harmful microbes. Just add this a few hours before adding
other nutrients so it can stabilize properly.
“If growers change
the water more often
than necessary,
THEIR WORKLOAD
AND NUTRIENT
COSTS GO UP.”
64
grow cycle
Liquid nutrient temperature is also very important in
water culture systems. The best range is 62-68°F. When the
temperature gets above 72°F, the dissolved oxygen will
drop. When the temperature gets below 60°F, it affects plant
metabolism and can change the state of growth.
Another aspect that has a major impact on the uptake of
many nutrients and needs to be carefully monitored is pH.
Because there is little buffering capacity when deep water
systems are filled, there are subsequently small microbial
populations or organic material to be converted—usually only
what the grower has added. The new water is usually low
in total alkalinity, which doesn’t help stabilize pH. With the
use of a total alkalinity buffering product (pH up), the pH of
the solution will tend to be much more stable and plant
uptake will be improved, causing plant health
and production to increase accordingly.
Nutrient buffering solutions with the addition of
agents like potassium carbonate not only increase
total alkalinity (total alkalinity is the measurement of
the amount of acid required to bring a solution down to a
pH of 4.1), but also increase the pH. So, if not compensated
for, these nutrient-buffering solutions may then make pH
too high. The acids needed to then bring the pH back into
the proper range will be found in products called pH down.
By using pH up and pH down products together, growers can
achieve the desired pH while also creating a more stable
solution through higher total alkalinity. Usually, the desirable
balance range for total alkalinity will be around 50-75 ppm
of calcium carbonate. There are inexpensive test kits for
measuring total alkalinity. Overall, the goal is to establish
a more stable water profile while keeping the pH within
the proper range (this varies for different plants but is often
between 6 and 6.5). The superior hydroponic practice is to get
to a stable total alkalinity and pH range quickly and then
maintain that through moderate use of the needed buffering
solution. Of course, your influent water may already be
within a stable range for pH control.
In water culture hydroponics, there are a number of differences
from other forms of indoor and hydroponic
systems. Cleaning, testing, adding
nutrients, and making adjustments are more
critical, but the rewards are definitely there
in the end. Hence why so many commercial
grow operations utilize these systems;
maximizing yield is top of their lists.