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Hydrogen Peroxide and Horticulture By Bryce Fredrickson

What Is Hydrogen
Peroxide? Hydrogen Peroxide (H2O2)
is a clear sharp smelling substance very similar
in appearance to water (H2O). Like water it is
made up of Hydrogen (H2) and Oxygen (O2),
however H2O2 has an extra Oxygen atom in an
unstable arrangement. It is this extra atom that
gives H2O2 its useful properties. H2O2 has been
used for many purposes including cleaning,
bleaching, sterilizing, rocket fuel, animal feed
treatment and in addition many miraculous claims
about its health benefits have been made. This
article isn't about any of these; instead it
will concentrate on horticultural applications.
H2O2 is of great use for both hydroponics and
dirt/soil less gardening.
What Does Hydrogen
Peroxide do? H2O2 is an unstable
molecule, when it breaks down a single oxygen
atom and a molecule of water is released. This
oxygen atom is extremely reactive and will
attach itself to either another O- atom forming
a stable Oxygen molecule or attack a nearby
organic molecule. Both the stable and O- forms
will increase the level of dissolved oxygen.
This is the method by which H2O2 is beneficial.
Pre treating the water supply with H2O2 will
drive out the Chlorine many cities use to
sterilize it. This will also degrade any
pesticides or herbicides that might be present
as well as any other organic matter. Well water
can be high in methane and organic sulfates,
both of which H2O2 will remove. Many disease
causing organisms and spores are killed by
Oxygen, the free Oxygen H2O2 releases is
extremely effective at this. H2O2 will help
eliminate existing infections and will help
prevent future ones. It is also useful for
suppressing algae growth. The free Oxygen atom
will destroy dead organic material (i.e, leaves
roots) in the system preventing them from
rotting and spreading diseases.
Over Watering
Roots require Oxygen to breathe and low
levels are the main cause of almost all root
diseases. Both soil and hydroponic plants often
fall prey to the same syndrome although it is
rarely recognized as what it really is.
Hydroponic crops often fail due to "root rot"
and soil crops succumb to "over watering." The
real cause of both these problems is a shortage
of Oxygen at the root zone. In a soil system the
soil consists of particles, a film of water on
the particles and air spaces between the
particles. When too much water is put into the
soil the air spaces fill with liquid. The roots
will quickly use up what Oxygen is dissolved in
the water, if they haven't drunk enough of the
liquid to allow air back in to the soil spaces
they will stop working. In this situation roots
will start dying within twenty-four hours. As
the roots die the plants ability to drink water
and nutrients will decrease, this will cause
symptoms of nutrient deficiencies (mostly pale,
slow, weak growth), and strangely they will
start to wilt like they don't have enough water.
It is easy to make a fatal mistake at this point
and add more water.
In a Hydroponic system the cause
is a more direct simple lack of oxygen in the
solution; this may be from inadequate
circulation and/or aeration. High reservoir
temperatures also interfere with Oxygen's
ability to dissolve in the water. Temperatures
above 70F (20C) will eventually cause problems,
62F-65F (16C-18C) is recommended. The same
symptoms will appear as with soil plants but you
can also check the roots. Healthy roots should
be mostly white with maybe a slight yellowish
tan tinge. If they are a brownish color with
dead tips or they easily pull away there is at
least the beginning of a serious problem. An
organic, ‘dirt like’ rotting smell means there
is already a very good chance it is too late. As
roots die and rot they eat Oxygen out of the
water, as Oxygen levels are even further
depleted more roots die, a viscous circle may be
well under way. Reduced Oxygen levels and high
temperatures both encourage anaerobic bacteria
and fungi. The plants may still be saved but you
will have to work fast.
How Hydrogen Peroxide
prevents root rot/over watering.
When plants are watered with H2O2
it will break down and release Oxygen into the
area around the roots. This helps stop the
Oxygen from being depleted in the water filled
air spaces until air can get back into them.
High Oxygen levels at the roots will encourage
rapid healthy root growth. In a Hydroponic
system H2O2 will disperse through out the system
and raise Oxygen levels as it breaks down.
Strong white healthy roots with lots of fuzzy
new growth will be visible. This fuzzy growth
has massive surface area allowing for rapid
absorption of the huge amounts of water and
nutrients needed for rapid top growth. A healthy
plant starts with a healthy root system.
How to use it.
H2O2 comes in several different
strengths 3%, 5%, 8% and 35%, also sold as food
grade Hydrogen Peroxide. The most economical is
35% which we recommend be diluted to three
percent before using, as at this high
concentration it can cause damage to skin and
clothing. When working with food grade H2O2 it
is very important that you clean up any spills
or splashes immediately, it will damage almost
anything very quickly. This is extra important
with skin and clothing. Skin will be temporarily
bleached pure white if not washed cleaned.
Gloves are strongly recommended when working
with any strong chemical.
Food grade H2O2 can be diluted to
three percent by mixing it one part to eleven
parts water (preferably distilled). The storage
container should be opaque to prevent light from
getting in and it must be able to hold some
pressure. If three-liter pop bottles are
available in your area they are ideal for mixing
and storing H2O2. There are twelve quarter
liters (250ml) in three liters, if you put in
one quarter liter H2O2 and eleven quarter liters
(250ml) water in the bottle it will full of
three percent H2O2 and the bottle can hold the
pressure that the H2O2 will generate. Three
percent Hydrogen Peroxide may be added at up to
three ml's per liter (2 1\2 tsp. Per gallon),
but it is recommended that you start at a lower
concentration and increase to full strength over
a few weeks. Use every watering even on fresh
cuttings. For hydroponics use every reservoir
change and replace twenty-five percent (one
quarter) every day. Example: In a 100L reservoir
you would add three hundred ml's (3%) H2O2when
changing the nutrient. You would then add
seventy-five ml's more every day.
Where to get
it. 35% food grade: called food
grade because it has no toxic impurities. Of
course your local hydroponics retailer, whom you
can locate over the web (there may be shipping
restrictions on high strength peroxides). The
local feed supplier may have it in small towns.
Prices range from fifteen dollars per quarter
liter to eighty dollars a gallon. One gallon
will treat up to fifty thousand liters of water.
3%5%, 8% Can be found at most
drugstores or pharmacies, prices start at a less
than a dollar for a one hundred-ml bottle that
will treat one hundred liters.
What to do if you already
have root rot.
In Dirt: Use
peroxide water with an anti-fungicide and a high
Phosphate fertilizer (9-45-15, 10-52-10, 0-60-0)
for root growth. Or any other product with
rooting hormone dissolved in it is helpful in
regrowing roots and is strongly recommended.
Water heavily until liquid pours out the bottom
of the pot. This sound like bad idea, but it
flushes out stagnant dead water and replaces it
with fresh highly oxygenated water. Don't let
plants sit in trays full of water, the soil will
absorb this water and stay too wet. Don't water
again until the pot feels light and the top inch
or two of the soil are dry.
In
Hydro: Change your nutrients. Add
H2O2 to the system. This will add oxygen and
chemically eat dead roots. If roots are badly
rotted and can be pulled away by hand you should
pull them off. They are already dead and will
only rot, causing further problems. Add a
fungicide to kill any fungus that is probably
present in the rotted tissue to prevent it from
spreading. Increase aeration of the water, get
an air pump and air stones, or more of them, for
the reservoir. An air stone under every plant is
usually very effective, but will require a
larger air pump. Models that will do from forty
to four hundred stones are available. Decrease
the reservoir temperature, oxygen dissolves
better in cold water and disease causing
organisms reproduce slower as well. A good
temperate range is 62F to 65F; anything above
70F will eventually cause a problem. It is also
a good idea to remove any wilty plants from the
system and put them on a separate reservoir so
they don't infect plants that are still healthy.
Summary The
key to big productive plants is a big healthy
root system and Hydrogen Peroxide is a great way
to keep your roots healthy. It is a must to
ensure the biggest best crops possible and to
increase the chances of your plants thriving to
harvest. Peroxide users will rarely lose plants
or crops to root disease and will harvest larger
and more consistent crops. |