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For
answers to your questions, or to place an order by phone, please
call
802-644-8443
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Visit
our store at: BareRoots Hydroponics
234 Page Hill Rd
Waterville VT, 05492
Please call us for directions
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Hydroponics
nutrient management
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As a general rule,
plants will have a higher nutrient requirement during cooler months, and
lower requirements in the hottest periods. Therefore, a stronger nutrient
solution should be maintained during winter, with a weaker solution during
the summer months when plants take up and transpire more water than nutrients.
Know
Your Crop Plant EC or cF may vary according to the stage of growth.
For example, cucumber prefer cF 20 when establishing, and cF 25 after
the first harvest. Between 3-7 weeks after first harvest, the optimum
cF is 17.
See Plants
FAQs for charts of plants that grow well together.
Nutrient
solution should be changed regularly. Between changes water levels will
decrease. When this occurs 1/2 strength nutrients should be added to raise
the level. When water evaporates or is used it raises the conductivity
level of the water and should be monitored carefully not to burn the plants.
Should
there be a requirement to flush the growing bed, the system should be
flushed with nutrients (run-to-waste) rather than water to avoid starving
or stressing the plants.
There
are 20 Mineral Elements needed for optimal plant growth. First we start
with the Macronutrients,
called such because they are required in large amounts.
|
Carbon
|
C
|
Component
of all organic compounds |
|
Oxygen
|
O
|
supplied
by air & water |
|
Hydrogen
|
H
|
That's
why its element #1 |
|
Nitrogen
|
N
|
Part
of chlorophyll, amino acids, proteins |
|
Phosphorus
|
P
|
Used in photosynthesis and almost all aspects of growth |
|
Potassium
|
K
|
Activates
enzymes, used in formation of sugar and starch |
|
Calcium
|
Ca
|
Used
in cell growth and division, part of cell wall |
|
Magnesium
|
Mg
|
Part
of chlorophyll, activates enzymes |
|
Sulfur
|
S
|
Part
of amino acids and proteins |
Then
we have the Micronutrients, called such because they are required in
trace amounts. These are also refereed to as trace elements.
| Boron |
B |
Affects reproduction |
| Chlorine |
Cl |
Aids in root
growth |
| Copper |
Cu |
Used in chlorophyl,
activates enzymes |
| Iron |
Fe |
Used in Photosynthesis |
| Manganese |
Mn |
Part of chlorophyll,
activates enzymes |
| Sodium |
Na |
Used for water
movement |
| Zinc |
Zn |
Part of enzymes,
used in auxins |
| Molybdenum |
Mo |
Used in nitrogen
fixation |
| Nickel |
Ni |
Liberates Nitrogen
|
| Cobalt |
Co |
Fixates Nitrogen |
| Silicon |
Si |
Makes tougher
cell walls: enhances heat and drought tolerance |
These
are common chemicals that can be used to mix your own nutrient formulas.
| CaNO3 |
Calcium
Nitrate |
| K2SO4 |
Potassium
Sulfate |
| KNO3 |
Potassium
Nitrate |
| KH2PO4 |
Mono
Potassium Phosphate |
| MgSO4 |
Magnesium
Sulfate |
| TE
|
Trace
elements |
| NH4NO3 |
Ammonium
Nitrate |
Here
are some common organic materials used as fertilizers and soil amendments.
|
Material
|
N
|
P
|
K
|
Notes
|
| Blood (dried
or meal) |
12-15
|
1.2
|
1
|
soluble |
| Bone meal (unsteamed) |
2-4
|
15
|
25
|
calcium,TE |
| Bone meal (steamed) |
2-3
|
18-25
|
.2%
|
Ca, TE |
| Canola meal |
0
|
1.2
|
1.3
|
iron, TE |
| Cottonseed
meal |
7
|
2
|
2
|
acidic |
| Ploultry manure
(dry) |
3-4
|
2-4
|
1.2
|
soluble, TE |
| Compost |
1-2
|
1
|
1
|
TE |
| Cow (Steer)
manure |
.6-2
|
.3
|
.5-1
|
excess salts |
| Coffee grounds |
2
|
.3
|
.7
|
acidic |
| Feathers (dry
or meal) |
12-15
|
0
|
0
|
some TE |
| Fish meal |
8
|
7
|
2
|
soluble |
| Goat manure |
.5
|
.4
|
.4
|
TE |
| Granite dust |
0
|
0
|
4-5
|
some TE |
| Potash rock |
0
|
6-8
|
0
|
some TE |
| Greensand (glauconite) |
-
|
1
|
5-7
|
iron,Mg,TE |
| Guano (Bat) |
2-5
|
8-10
|
1-2
|
soluble, TE |
| Guano (sea
bird) |
10-15
|
5
|
2
|
soluble, TE |
| Hoof &
horn meal |
6-15
|
2
|
0
|
TE |
| Paper ash |
0
|
.1
|
2-3
|
High pH |
| Soft phosphate |
0
|
18-24
|
0
|
calcium,TE |
| Seaweed (liquid) |
.5
|
.5
|
.3
|
soluble, TE |
| Seaweed (meal) |
1
|
1
|
1
|
soluble, TE |
| Sheep manure |
.8
|
.4
|
.5
|
TE |
| Swine manure |
.6
|
.4
|
.5
|
TE |
| Wood ash (hardwood) |
0
|
1.5
|
7-10
|
soluble |
| Wood ash (softwood) |
0
|
.8
|
5
|
soluble |
| Worm castings |
3.5
|
1
|
1
|
TE |
*TE
= Trace Elements also called micronutrients.
|
MAX
RANGE DESIRABLE PERMISSIBLE
( Measured levels for hydroponic nutrients.)
|
EC
as mS
0.75
to 2.0
|
TDS
as PPM
500
to 1300
|
|
(with
potential for concern)
|
2.0
to 3.0
|
1300
to 2000
|
|
PROBABLE
SALT DAMAGE
|
3.0
and up
|
2000
and up
|
1 mS
= 10 cF = 700 PPM
EC =
Electrical Conductivity
mS =
Milli Siemens
cF =
Conductivity Factor
TDS =
Total Dissolved Salts
PPM =
Parts Per Million
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