Nutrients
No matter where or how you grow your plants, they require nutrients. In soil, these are obtained from decomposing
organic matter, whereas in hydroponics they need to be fed to the plants in a water solution. This, therefore, is the
most crucial element to growing plants hydroponically.
What do plants require?
Scientists and botanists have discovered that plants require a total of sixteen essential elements in significant
amounts to grow healthily. There are numerous other elements required in minute quantities but for the purposes of
hydroponics we will concentrate on the sixteen essential elements.
- Oxygen
- Carbon
If the plant is exposed to light, up to 4 times the amount of CO2 found in the air is beneficial to the plant.
- Hydrogen
These three elements (above) are supplied by the environment around the plant and are used by plants to photosynthesise,
converting light energy (either sunlight or artificial light) into carbohydrates using these three elements.
- Nitrogen
Greater quantities required in strong light.
- Phosphorous
Utilised in low light conditions
- Potassium
Utilised in low light conditions.
- Calcium
- Magnesium
- Sulphur
The following seven are considered as minor/trace elements.
- Iron
- Manganese
- Copper
If supplied in excess it is extremely toxic to the plant.
- Zinc
- Boron
- Molybdenum
- Chlorine
If supplied in excess it is extremely detrimental to the plant.
There are two basic types of plant food: solid powders/granules and water based liquid nutrients. When considering
nutrients the three most important elements are Nitrogen (N), Phosphorous (P) and Potassium (K).
What do those numbers on Nutrient labels mean?
When you purchase nutrients, there are three numbers printed on the label. These refer to the quantities of N-P-K
in the nutrient. For example, Advanced Nutrients Sensi One (Part B) displays 2.5-2.2-5.7. This indicates that 2.5% of
the solution is Nitrogen, 2.2% is Phosphorous and 5.7% is Potassium. They are always displayed in the same order of
N-P-K, so there should be little confusion.
There are as many nutrients on the market today as there are opinions on which nutrients are the best to use.
Your choice of nutrients is generally down to personal preference and experience with what works best for you.
Below are a few basic guidelines:
- One Part Nutrients
Ideal for beginners and the less experienced hydoponic growers. These nutrients contain everything needed to get you
started.
- Two Part Nutrients
Slightly more advanced enabling the grower to control the nutrients a plant receives, depending on whether the plant
is in a vegetative/growing stage or in a bloom/flowering stage.
- Three Part Nutrients
Generally used by commercial / professional horticulturists, allowing for complete control of the plants' nutrient
intake depending on its stage of growth. These are considerably more precise and require experience and knowledge of
the plants you are growing and what elements the plant needs for the differing stages of growth.
Two and Three part nutrients are split into their separate parts because certain elements contained within them will
precipitate in concentrated forms, but once diluted into solutions all will be well.
The Plants' Life Cycle and Elements Required
As a guideline, plants require more nitrogen during the early stages of growth - also known as the vegetative stage.
During flowering, greater quantities of phosphorous, potassium and magnesium are essential. One point to note is that
throughout the plants' life, the other elements are necessary for the plant, but all available hydroponics nutrients
have varying degrees of these elements mixed in with the major three, depending on what the manufacturers believe is
most beneficial to their product. The majority of nutrient brands supply their nutrients in both Grow and Bloom
varieties, making it easier for all of us to apply the correct elements at the correct stages of the plant cycle.
Be aware that it is possible to both overfeed and underfeed nutrients to your plants with varying effects. Nutrient
burn from overfeeding tends to be more common.
pH levels and the cF factor/EC levels
pH levels in gardening are important. In soil gardening the soil acts as a buffer for pH levels, whereas in
hydroponics the growing mediums used are inert, therefore keeping control of the pH level increases. The pH does
directly influence the plants' capability to uptake nutrients as well as affecting the availability of nutrients.
For example, at high pH levels, iron becomes non-existent due to precipitation, and root damage is nearly inevitable
at low pH levels. Therefore, a pH level of about pH6 is generally recommended for hydroponic solutions.
There are numerous products for recording and adjusting pH levels on the market, varying in levels of accuracy and
expense. Note: pH levels do change throughout the day and night, so for more accurate readings, you are advised to take
your readings at the same time of day/night.
Measuring and recording your solution pH levels is very easy, whichever method you choose to use, and takes very
little time and the resulting health of your plants makes it very rewarding for the grower.
cF (Conductivity Factor) is a measurement of the solution strength. The cF is critical to growing plants at their
optimum levels and is individual to each different species of plant and the kind of growth required. Hydroponic
nutrient solutions are measured by passing an electrical current through the solution. This can be measured by an
EC (Electrical Conductivity) meter, which gives readings as cF, EC or ppm (parts per million), indicating the strength
of the solution but not the individual percentages of the elements contained. Expensive meters will be able to read all
three. Or you could just follow the recommended amounts of solution given by the manufacturers of the nutrients you buy,
supplied with the bottle!
A word on Additives / Supplements
Additives and supplements are exactly what they say they are - to be added to and/or supplement your nutrient
solutions to obtain the best growing results from your plants. There are too many on the market to explain in detail
here, but they all tend to perform specific tasks from promoting the plants uptake of nutrients, and strengthening
roots to inducing flowering and increasing the quantities of minor elements required by your plants. The descriptions
found on this website for individual products should give you an idea of their purpose. They are considered an integral
part of the growing process and are necessary for optimum results.
Any further questions you may have, please drop us a line using the form on our contact us page.
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