What is hydroponics?
"A technique of growing plants in nutrient solution”.
Hydroponics literally means water-working or water-activation. It is a
cultivation technique for growing plants in highly oxygenated, nutrient enriched
water, rather than soil.
The nutrient solution and its management are the
cornerstone for a successful hydroponics system. The function of a hydroponics
nutrient solution is to supply the plant roots with water, oxygen and essential
mineral elements in soluble form.
In soil, biological decomposition breaks down organic
matter into basic nutrients that plants feed on. Water dissolves these nutrients
which allows uptake by the roots. For a plant to receive a well balanced diet,
everything in the soil must be in perfect balance.
Depending on the product, there are approximately
seventeen (17) required elements for proper growth. For growth of higher plants,
nine of these elements (macro nutrients) carbons, hydrogen, oxygen, sulfur,
phosphorus, calcium, magnesium, potassium, and nitrogen are required in
relatively large amounts. The remaining eight elements (micro-nutrients or trace
elements) iron, zinc, copper, manganese, boron, chlorine, cobalt, and molybdenum
are needed in only minute amounts.
To support a plant in a system, an insert medium like
fiber or leca, may be used to anchor the roots. These mediums are designed to be
very porous for excellent retention of air and water for healthy plants-roots to
breathe! With the proper light exposure, nutrients, pH and EC/TDS measurements,
plants will grow many times faster, bigger and healthier.
pH? Why is it important?
pH, means “potential hydrogen” ion concentration (commonly
referred to as acidity or alkalinity) in a particular medium, such as water,
soil, etc. All elements have a specific solubility pH range. This means that
mineral elements can become more available for plant uptake within certain pH
ranges. The scale of pH is 0 to 14, 14 is the highest for alkalinity, 7 is
neutral, and 0 is the highest acidity. It is well documented that growing media
pH is critical to successful plant growth. This is especially true for soilless
mixes and hydroponics.
Extreme pH conditions such as very low pH (below pH 4.5)
and very high pH (above pH 9) can cause damage to plant roots and limit or kill
What is Electrical Conductivity (EC) or Total Dissolved Solids (TDS)? Why is it
EC [displayed in either microsiemens (μS) or micromhos (μM)]
is the measurement of the nutrient solutions ability to conduct an electrical
current. In hydroponics the conductivity (EC) is most commonly expressed in an
equivalent Total Dissolved Solids (TDS) value. The unit of measurement for TDS
is parts per million (ppm). Pure water (deionized water) is actually an
insulator — it does not conduct electricity. It is the conductive substances (or
ionized salts) dissolved in the water that determine how conductive the solution
is. With few exceptions, when there is a greater concentration of nutrients, the
electrical current will flow faster, and when there is a lower concentration,
the current will flow slower.
This is because the quantity of dissolved solids in the
nutrient solution is directly proportional to the conductivity. Thus, by
measuring the EC, one can determine how strong or weak the concentration of the
nutrient solution is.
How is EC converted to ppm of TDS?
Myron L® Company instrumentation uses a complex equation
that exactly matches the true TDS of the solution being tested. While other
instrument manufacturers use a “fixed” factor (easier and less costly to
manufacture) to “estimate” the TDS from electrical conductivity. As you can see
in the following examples a fixed factor of, for example .5 is far off the mark.
Temperature Compensation (TC), why
is it important?
Without Temperature Compensation (TC), instrumentation measuring
waters/nutrients would be indicating different values at differing temperatures.
TC standardizes the readings at the international standard of 25°C / 77°F. With
proper TC all readings will be repeatable at differing temperatures and may be
correlated. All Myron L® instruments use advanced TC circuitry and equations to
give you the best TC correction available.
Calibration Standard Solutions
Clearly the “BEST” choice when calibrating instrumentation for controlling
water and nutrients in Hydroponics, Greenhouses and Agricultural applications is
the “442™” natural water standard.
This standard developed over 40 years ago by the Myron L® Company closely
matches the composition of natural water. The “442” refers to the combination of
salts with deionized water to make the standard: 40% sodium sulfate, 40% sodium
bicarbonate, and 20% sodium chloride. Since its development, it has become the
world’s most accepted natural water standard. All
HYDROPONICS Instruments from
the Myron L® Company are calibrated using this standard.
For truly accurate and repeatable readings for your
use Myron L® Company instrumentation and “442” Standard Solutions.
All instrumentation, pH buffers and EC/TDS standards are available from the
Myron L® Company and our worldwide distribution network.