Table Of ContentNUTRIENTS FOR
HYDROPONICS
a n d t i s s u e c u l t u r e
BY JOhN MaSON aNd STaFF OF aCS dISTaNCE EdUCaTION
Contents
Preface 6
CHAPteR 1 IntRoduCtIon 7
Artificial Growing 7
Tissue Culture 8
Hydroponics 8
How Plants Uptake Nutrients 9
How Plants Absorb and Use Nutrients in Hydroponics 11
Hydroponics Techniques 11
CHAPteR 2 PRe-PACkAged nutRIents 18
Using Solid Nutrients 18
Solutions and Precipitates 18
Why Twin-Pack Chemicals? 19
Why Single-Pack Liquid Solutions? 19
Organic Solutions 19
CHAPteR 3 CHemICAl ComPonents 21
Types of Chemicals 21
Electrical Conductivity 23
The Role of pH in Hydroponics 25
What Are Solutions? 26
What Does a Hydroponic Nutrient Look Like? 26
Writing Chemical Names 28
Calculating the Amount of Nutrient in a Chemical 29
Mixing Nutrients 32
Hydroponic Fertiliser details 32
CHAPteR 4 otHeR AddItIves 35
Introduction 35
Allowable Additives for Hydroponic Nutrient Solutions 36
Beneficial Trace Elements as Hydroponic Additives 40
Bio-stimulants as Hydroponic Additives 40
Foliar Nutrition and Foliar sprays 42
CHAPteR 5 CReAtIng HydRoPonIC nutRIents 44
Introduction to Basic Mixes 44
Process of Making and Mixing Nutrients from Fertiliser Salts 45
Example Solutions 46
Nutrient Solution Formulation 53
Hydroponic Nutrient Levels 53
Nutrient Ratios 55
Assessing a Nutrient Formulation 56
Suggestions for Beginners 57
CHAPteR 6 oRgAnIC HydRoPonIC nutRIents 58
Brief History 58
Issues with Organics 58
Types of Organic Systems 59
Allowable Nutrient Sources and Products for Organic Production 60
Making Organic Nutrient Solutions Onsite 61
EC and pH Control in Organic Hydroponics 62
Problems with Organic Nutrients 62
CHAPteR 7 tIssue CultuRe nutRIents 64
Hydroponics vs. Tissue Culture 64
Nutrient Supply in Tissue Culture 65
A Tissue Culture Medium 66
Other Additives in Tissue Culture and Hydroponics 66
Organic Compounds 67
CHAPteR 8 mAnAgIng ContAmInAnts 68
Water Quality 68
Disinfection Systems 71
Preventing Chemical Contaminants from Leaking into the Broader Environment 73
CHAPteR 9 testIng solutIons 74
Important Tests in Hydroponics 74
Water Quality Tests 74
Water quality test results and interpretation 75
Nutrient Balance Testing: Solution Analysis 78
Plant Testing: Foliar Mineral Levels 79
pH Tests for Hydroponics 80
EC Testing 81
Automatic EC and pH testing and control 81
CHAPteR 10 nutRItIonAl dIsoRdeRs 82
Nutrition Management 82
Diagnosing Nutritional Stress 83
Nutritional Deficiencies 83
Macronutrients: NPK Deficiencies and Toxicities 85
Other Common Deficiencies and Toxicities 89
Micronutrients 90
What are the Most Common Symptoms? 92
Key to Detecting Deficiencies and Toxicities 93
CHAPteR 11 nutRIent solutIon And PRoduCe nutRItIon 95
Examples of Nutrient Solution Manipulation and Produce Nutrition 95
FuRtHeR ReAdIng And study 99
More ebooks available 99
Courses available 99
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CRedIts
© Copyright 2018 John Mason The information in this book is derived
from a broad cross-section of resources
Photos: (research, reference materials
John Mason and Stephen Mason and personal experience) from the
authors and editorial assistants in the
layout & Illustration: academic department of ACS Distance
Stephen Mason Education. It is, to the best of our
knowledge, composed as an accurate
Contributors representation of what is accepted
John Mason Dip.Hort.Sc., FCIH, FAIH and appropriate information about the
Dr Lyn Morgan B.Hort.Tech., PhD. subject, at the time of publication.
Adriana Fraser Adv.Dip.Hort.
Marie Beerman B.Hort., M.Hort. The authors fully recognise that
Peta Jinnath Abdul B.Sc. knowledge is continually changing,
Mitchell Skiller Ass.Dip.Hort. and awareness in all areas of study
Gavin Cole B.Sc., M. Psych. is constantly evolving. As such, we
encourage the reader to recognise
Published by: that nothing they read should ever
ACS Distance Education be considered to be set in stone.
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by the reader based upon their reading
ISBN: 978-0-6483232-2-8
of this book.
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PReFACe
Plants naturally grow in soil, but modern
science has found other ways for them
to grow.
Once you understand what things soil
does for plants, you can then with
the help of modern science begin to
conceive other ways of doing those
things, replacing the need for soil.
The main thing soil does for a plant is
to provide nutrients. It also provides a
place for the roots to anchor the plant,
and an environment to insulate the
roots from extreme weather and provide
moisture and oxygen for the roots
to absorb.
Hydroponics and tissue culture are
modern ways of growing plants without
soil. They offer the grower many
advantages, not the least an ability
to have greater control over how the
plant grows.
Pivotal to that control, is to understand
and manage the nutrients provided to
the plant. This management of nutrients
is what this book is about.
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CHAPteR 1 IntRoduCtIon
Plants, like any living thing, need food to grow. In nature, such plant
food comes from the soil. If we grow a plant using tissue culture or
hydroponics, there is no soil as such, meaning the nutrients must be
supplied artificially.
Hydroponics
Artificial Growing
pathogens). It also presents the
challenge of trying to balance what is
Artificial growing provides the supplied and how it is supplied.
advantage of having total control
over the nutrients the plant does and Artificial growing can be more
does not get. This also provides an complicated, but if managed really well,
opportunity to add other things into a it provides opportunities that do not
chemical solution (e.g. hormones to exist when you grow plants in soil.
regulate growth, chemicals to control
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Plants obtain nutrients two ways: them. The tissue used does not contain
plant parts like roots, stems and leaves
1. Through the roots – mostly mineral but rather just cells from roots, stems or
salts dissolved in water are absorbed leaves. Or it may contain undifferentiated
through roots. meristematic tissue (like stem cells from
a human). Plants cultivated this way will
2. Through foliage – mostly carbon require both a mixture of nutrients to
dioxide and oxygen gasses are feed them and other chemical additives:
absorbed through foliage. vitamins, carbon, sometimes hormones
(growth regulators to encourage cell
Note: Oxygen and carbon dioxide can differentiation), sometimes specific
be absorbed through roots to some reagents to restrict growth so as to
extent. Water and other nutrients can be stimulate them to grow all the different
absorbed through foliage too. types of cells needed to become
a complete plant (i.e. roots, stems
Other than Carbon (C), Oxygen (O), and leaves). This makes the culture
and Hydrogen (H), plants need a range medium and medium formula used
of macro and micronutrients in order the most crucial aspects of successful
to grow well. The six macronutrients tissue culture; the medium formulae
(needed by plants in larger amounts) vary depending on the purpose of the
are: Nitrogen (N), Phosphorus (P), tissue culture.
Potassium (K), Magnesium (Mg),
Calcium (Ca), and Sulphur (S). Because a plant grown this way is
incomplete, and very tiny, it is particularly
Micronutrients (or trace elements) are vulnerable to diseases; hence it needs
taken up in much smaller (even minute) to be grown under laboratory conditions
amounts and include Iron (Fe), Zinc (Zn), until it is large enough to resist disease,
Manganese (Mn), Copper (Cu), Boron absorb nutrients through developing
(B), Molybdenum (Mo) and Chlorine (Cl). roots and continue to grow without a high
level of assistance.
Most soils have ample quantities of
calcium and magnesium and therefore
fertilisers used in general horticulture
are almost completely made up of
nitrogen, phosphorus and potassium
(NPK). In hydroponics though, it
becomes necessary to add large
amounts of magnesium and calcium.
tissue Culture
Tissue culture is a method of propagating
and growing plants from small pieces
of plant tissue, sometimes so small that
Tissue Culture
magnification is necessary when handling
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Hydroponics
less of one type of tissue (e.g. leaves,
flowers, fruit).
Hydroponics involves growing plants
without soil; but it is different to tissue
How Plants Uptake
culture in that the plants have fully
nutrients
differentiated tissues (i.e. stems, roots
and leaves) from the start; and the
plants are larger and more able to To gain a better understanding on
grow without the level of protection and how to formulate and supply nutrients
human intervention provided for tissue to plants in the rates that are needed
culture in a laboratory. for good, healthy plant growth in
hydroponics – you need to know, in a
Both tissue culture and hydroponics general sense, how plants uptake and
share one thing in common – the grower use nutrients.
is taking control over supplying nutrients
to the plant. In doing so, the grower has Nutrients available to the plant vary
the potential to manage the plant growth depending on the chemical and physical
more effectively that what is possible nature of the environment, the species
when growing is soil. being grown and its stage of growth.
Plants obtain a substantial portion of
Nevertheless, every plant species is their oxygen from the atmosphere.
different and has different nutritional The remainder of nutrients, including
requirements. Therefore, the optimum hydrogen, required for plant growth
nutrition required by each type of plant absorbed from soluble elements in water.
will be different. The nutrients made
available by soil, or by feeding plants Light intensity, temperature and water
can have a big impact on the status of a supply determine how effective plants
plant in many different respects: are at using available nutrients. Nutrients
and water absorbed are translocated
● Vigour through the plant dependent on the
relationship with the membranes and
● Tolerance to different types of the solution, and the concentration of
adversity (e.g. environmental nutrient ions around a plants root zone.
extremes, disease)
Plant nutrients can be supplied, broadly
● Type of growth (e.g. fruit, flower, speaking, in three different forms:
foliage, roots)
1) Water-soluble simple chemical
● The quantities of different chemicals compounds: nutrients in these
found in the plant tissues compounds are readily available to
plants (i.e. the plant can absorb them
The nutrients which a plant absorbs and quickly and easily).
incorporates into its tissues will affect
its chemical composition. Food crops, 2) Less soluble simple chemical
for example, can become more or less compounds: the nutrients in these
nutritious. Plants may develop more or compounds can be used by plants
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without needing to undergo any chemical and root interception.
change, but because they don’t dissolve
so easily in water, they aren’t as readily Mass flow: this is the most important
useable as the more soluble compounds. of these mechanisms quantitywise, and
The diminished solubility may be is the movement of plant nutrients in
because of the nature of the compound flowing soil solution.
(e.g. superphosphate) or may be due
to something else (e.g. slow-release Diffusion: this is movement by normal
fertilisers, such as Osmocote, which dispersion of the nutrient from a
are made by incorporating the simple higher concentration (such as near its
chemicals inside a semipermeable bubble dissolving mineral source) through soil
where nutrients move slowly out of the water to areas of lower concentration of
bubble). This second group of nutrients that nutrient. It is different to osmosis
when placed in soil will last longer than which is where solvent molecules
the first group of water-soluble nutrients. will move through a semipermeable
membrane from a region of low solute
3) Complex chemical compounds: concentration to a region of high solute
these require chemical changes to concentration.
occur before the nutrients can be
absorbed by plants. They include Root interception: this is the extension
organic manures and fertilisers which (growth) of plant roots into new soil
need to be broken down by soil areas where there are untapped
microorganisms into a form which the supplies of nutrients in the soil solution.
plant can use. They also include other
complex fertilisers which need to be All three processes are in constant
affected by natural acids in the soil, or operation during growth. The
heat from the sun, to become simple importance of each mechanism in
compounds which the plant roots can supplying nutrients to the root surface
use. Complex chemicals release their for absorption by the root varies with the
nutrients gradually over a long period chemical properties of each nutrient.
of time, depending on the range of Nevertheless, mass flow, because of
chemical changes needed to take place the large amounts of water flowing
before the plant can use them. Plants to, and absorbed by, roots as water is
grown in soil derive their nutrients from transpired from the plant is the dominant
all three types of compounds. The mechanism and supplies about 80% of
availability of these compounds varies most nutrients to root surfaces.
according to not only the group they
come from but also according to factors The mechanisms of absorption into
such as heat, water, soil acids and the root cells are not well understood.
microorganisms present. As such, it is The cell walls are porous, and the soil
impossible to control the availability of solution can move through some or
nutrients in soil to any great degree. all of the cell walls, causing intimate
contact of the soil solution with the
Prior to their absorption into root cells, outer membranes of the cells. For a
nutrients reach the surface of roots by nutrient to cross a cell membrane into
three mechanisms: mass flow, diffusion, the cell, it is believed that each nutrient
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