FEATURESTORY
by Andrew Taylor
Creating the Perfect Nutrient Solution
for the Veg and Flower Stages
T
he performance of a nutrient solution is
not guaranteed by simply using a quality
brand. Proper dosing procedures and on-
going maintenance are necessary to obtain
maximum performance.
Always use a Professional Liquid Nutirent
Ideally one formulated specifically for use with
the medium being used. Be sure to use the associated
additives as overall performance will often depend
on these. The order in which you add different com-
ponents is important, and so is the timing—seedling,
vegetative or bloom. Always follow the dosage chart.
Use Clean and Sterile Water
This helps to prevent diseases. Use either fresh re-
verse osmosis water (ideal due to its low nuisance salt
content) or fresh treated tap water.
Add Nutrients and Additives to Water
Always add the majority of water before adding
nutrients and additives. Never mix any nutrients or
additives together in their concentrated form. Once a
nutrient or additive is added to the water, stir it well
before adding the next. High pH additives should
be added last, pre-diluted into a cup of water before
being added, quickly stirred and the pH checked (Fig
2).
Measure the Nutrient Solution Strength (EC)
and pH.
Check this once the total solution is made and ‘be-
fore’ feeding it to the plants. For most species, use the
following as a guide:
◆ ◆ pH: Maintain between 5.0 to 6.5. Within this range
all essential nutrient elements will remain soluble
and available for root uptake (see Fig 1). To ad-
just pH, add pH Down (often required) or pH Up
(rarely required). Add little by little until the pH
falls within the correct range. To measure pH use
a digital pH meter that has been calibrated in pH
Buffer 4.0 and pH Buffer 7.0 (essential for accu-
racy).
◆ ◆ Nutrient strength (EC): Test using a conductiv-
ity (EC, mS, cF) or TDS meter. For seedlings or
clones use 0.6 to 0.9mS. For the vegetative phase
38
use 1.3 to 1.8mS. For flower use 1.8 to 2.4mS (Use
the lower levels during heatwaves or if plants are
stressed). The “meter” reading indicates the con-
centration of salt based solutions. Hence, a higher
reading implies a higher concentration. Therefore,
if your meter’s reading is too low, simply add
more nutrient. Obviously if it is too high then add
more water. TIP: Always stir the nutrient solution
well before taking readings.
◆ ◆ For recirculating hydroponic systems only: As
plants grow they simultaneously remove both
water and nutrients from the nutrient solution.
Ensure the water level is kept relatively constant.
When this is done, the concentration (EC) will be
relatively predictable. It will move up or down de-
pending upon the size and growth rate of plants
and the salinity of the top-up water.
Tepid Solution
Use a nutrient thermometer to monitor the tem-
perature of your nutrient solution. The ideal is 68° F
(20° C). Too warm and you risk promoting root dis-
eases or suffocating the root zone with low dissolved
oxygen levels. Too cold and you will shock the roots
and slow plant metabolism to a crawl. Your nutrient
www.GardenandGreenhouse.net
April 2018