Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
Hydroponics is the art of cultivating plants without soil, delivering their
nutrient requirements via custom-formulated liquid nutrient solutions, resulting in a perfectly balanced diet delivered at regular intervals.
This means the crop doesn’t need to continually spend energy
producing new roots to find new food and isn’t reliant on an army of microbes that demand a tight set of parameters to be fully active within
your soil to release the required nutrients.
Cultivating crops commercially is usually done using hydroponic
techniques because it allows precise control over the end product and
more predictable output in terms of yield and quality.
All hydroponic systems have one thing in common: they have a nutrient reservoir with pumps on timers to feed the crop at set intervals
throughout the day. The nutrients are usually mineral-based blends
with a nitrogen dominant recipe for growing and a potassium and
phosphorus dominant recipe for flowering/fruiting plants.
Hydroponic Grow MediumA suitable hydroponic grow medium needs to be inert ( contain no
nutrients), light and airy and hold water. There is a wide range of media
suitable, such as tree bark, peat and moss, small cubes of foam, rock
wool or expanded clay rocks. But, by far the most popular growing
medium is coconut coir.
Coconut coir
Coir is a byproduct of coconut harvesting. The outer husk is fibrous and
has a perfect air to water ratio, meaning it can never be waterlogged like
soil can. It will always contain at least 30% air content because 30% of the fibres are water repellant.
During the processing of coir, various grades are created, from fine coir
peat to thick croutons. Coir insulates the roots from temperature
extremes and has a good CEC (cation exchange capacity) rating. This
means that it can hold onto nutrients and release them to the plant between feeds, increasing nutrient availability and efficiency.
A lot of the solution is held within the pot available for the plant to use
between feed cycles and doesn’t simply run straight through and be
wasted.
Buffer your Coir
The only negative about coir is that it can contain a high sodium level. We can flush this away and replace it with beneficial minerals, or it will steal them from your first feeds. Most coirs are buffered but making
sure can only be beneficial to your results.
Rockwool
As the name suggests, this is created when basalt rocks are heated to
extreme temperatures in a furnace and streams of air are blown
through them resulting in separating the layers of molten rock to create
a textile-like structure that retains moisture and air. Alternatively, they
are spun in a custom machine that spins molten rock, sort of like how
candy floss is made.
The end product is then cut into the required size. The method used to
layer the spun rock fibers and the density in which they are laid
determines the end products water holding characteristics.
This enables rockwool to be produced to suit a huge range of commercial crops from light and airy to dense and wet. The moisture
gradient difference between the top layers and the base layers of rockwool is what makes it so ideal as a hydroponic medium.
A properly irrigated rockwool slab will retain plenty of moisture within
the bottom 35% 3 of the slab and be almost dry towards the top. This
facilitates explosive rooting and means the plants can easily draw
moisture from the slab even when the moisture content is low. Rockwool is available in a huge array of products from propagation
cubes for clones and seedlings to cubes of various sizes and even 1m
long slabs.
Drain it before use and do not squeeze dry it or you ruin its open pore
structure, which is its main advantage.
Rockwool must be pre-treated prior to use because it has a Ph OF
9.0! Before use, soak in a solution with a Ph. OF 4.0 for 12 hours =
ph. 6.0
Expanded Clay Correls
These are manufactured by baking small balls of clay at high
temperatures, resulting in them expanding before consolidating into a
hard, lightweight clay ball that has a honeycomb-like structure.
This is perfect for aeration and for beneficial microbe colonies. They
retain water and are used to improve the texture of other grow
mediums like soil or coir. Besides being used to aid drainage in pot culture, they are used mainly in flood and drain, aeroponics or deep
water culture systems.
There are a few more substances used as hydroponic growing mediums
such as perlite or sphagnum moss.
Water QualityTrace minerals in the supply water can vary greatly at different sites: hard water contains higher levels of bicarbonates and soft water has
lower concentrations of bicarbonate
Hard Water
If you are growing in hard water the pH has a tendency to rise towards
7.0 because of the higher bicarbonate levels. If using hard water, mixing
your fresh reservoir to a pH 5.2 will neutralize the bicarbonates and
stabilize the PH resulting in a gradual rise in PH over days instead of hours.
Soft Water
When mixing your reservoir using soft water it is best to set the pH to
5.8 and let it drift to 6.2 before adjusting back to 5.8. Soft water has a
tendency to drop in 4 pH which is why you should adjust using pH UP
which increases the buffering capacity of soft water resulting in a more
stable pH.
Reverse Osmosis
If you use RO water for your hydroponics system, you will need to buffer
it to stabilize the pH, due to the lack of minerals in it. Adding 0.4EC of CalMag to your reservoir prior to dosing with nutrients will achieve this.
pH ManagementPH Management Nutrient solutions are made up of blends of minerals. Each of these minerals when mixed with water has its own pH, which
can range from pH 3.0 to 9! So, blending a nutrient solution is a
balancing act. In chemistry, pH stands for Potential Hydrogen and is a
measure of how acidic/basic water is. The range goes from 0 to 14, with
7 being neutral. A pH value of less than 7 indicates acidity, whereas a pH
of greater than 7 indicates a base.
A well-balanced nutrient solution will have a stable pH when mixed to
the recommended concentration.
However, in a recirculating system, in growth stage, over time it will drift towards pH 7.0 because the plants’ roots excrete a compound that is
alkaline, and acidic minerals are consumed by the plant, making the pH
rise.
Then in the bloom stage, the opposite happens, and the plants excrete
compounds that are acidic and the pH will slowly lower to be more
acidic. When using well-formulated grow and bloom feeds, this is taken
into account to try to 5 balance the pH.
Too low pH (below 5.2)
Don't let your pH get too low as aluminium, iron and manganese can
become more available, resulting in your plants consuming toxic
amounts of these elements.
This will result in over-fertilization and nutrient lockout.
Too high pH (above 7.8)
If your pH rises above 7.8 you will start to notice white clouds forming in
your reservoir. This is your calcium falling out of solution; the process is
called precipitation.
Once this happens your precipitated minerals are rendered unavailable
to your plants and your nutrient solution pH will become erratic as its
buffering capacity is reduced and your minerals are now unbalanced.
Adjusting pHThere are a number of chemicals that are used as pH adjusters with the
most popular being:
pH Down (acid) - phosphoric acid 89%
This is the most popular pH Down product and is super concentrated. You MUST be very careful with this as a little can make a big difference
to the pH, especially in small reservoirs or small bucket batches. I always
suggest keeping a 500ml empty soda bottle and dilute 50 ml and top it up with water for a more gentle adjustment solution.
pH UP (alkaline) - potassium hydroxide
You add this in small amounts to raise the pH of your solution. It is very
unlikely you will need this in usual grow situations. But if you do use it I find it best to dilute it into 500ml of water before adding it to your
reservoir as this will avoid localised precipitation happening.
Nutrient Strength ECAs well as balancing the acidity ( pH ), the nutrient solution strength also
needs to be monitored and managed to keep within an ideal range for
your crop. The more nutrients (salts) that are added to the water the
higher the conductivity will be.
EC (Electrical Conductivity)
The amount of minerals in your nutrient solution is measured by an EC
pen, 6 which measures a small electrical current between 2 points to
determine nutrient strength and is measured in mS/cm or millisiemens
per centimetre.
TDS stands for Total Dissolved Solids and is measured in PPM or parts
per million.
On top of that, there are three different conversion factors to determine
TDS and different manufacturers use different conversion factors.
EC - Electrical Conductivity standard: mS/cm or millisiemens.
PPM (Parts per MIllion):(ECx700) - this is exactly the same method of measurement but converted to display the concentration in parts per
million parts of water. 140ppm is 0.2 EC.
TDS (Total Dissolved Solids) Uses the ppm (EC x500 conversion factor) so if you are using a TDS pen 100ppm is 0.2 EC.
Maintaining ideal nutrient strength for the crop you are growing is
important. Each species of plant has an ideal nutrient requirement.
Ensuring you stay within your plants' ideal range will save burning your
plants and stunting growth.
Too many accumulated minerals in your grow medium will become
acidic and damage your roots and throw your runoff solution out of balance. This is especially important if you are recirculating your
nutrients back into your reservoir. Don’t stress too much over the detail, just get a EC pen or truncheon: it is a valuable tool for diagnosing plant problems and it is always wise to monitor input and output EC and pH
values to really understand what is happening at the root zone.
If you really want to learn hydroponics, I would strongly suggest you
invest in some good test equipment. Don’t choose the cheapest available, it’s a false economy if it costs you a crop because your pH was
off all the way through. Buy quality, keep it clean, they will be your
friends.
Recirculating HydroponicsThere are two nutrient management methods used in hydroponics:
Recirculating
Run to Waste
Recirculating Systems
With this system, you will fill your reservoir with nutrient solution and
after each irrigation cycle, the excess runoff water is returned to the
nutrient reservoir. This method needs regular checks and adjustments
to the pH and EC to keep them within the ideal range.
In commercial setups, these systems will be computer monitored, topped up and dosed with nutrients and pH adjustment solutions after
each irrigation 7 cycle, but in the hobby situation, I recommend topping
off regularly and adjusting your EC and PH manually.
Advantages of this system are the cost and water saving. Growing
crops in a recirculating system are one of the most water-efficient methods available and use the minimum amount of nutrients when
compared with the run to waste.
The disadvantages of recirculating are the constant requirement to
readjust your EC and pH each day after multiple irrigation cycles have
returned unbalanced waste nutrients back to your reservoir.
After each irrigation your plants take minerals from your solution so the
waste solution becomes out of balance and must be managed well, or
totally replaced and refreshed regularly, to ensure your plants receive
balanced nutrition.
Solutions
Improving nutrient stability in recirculating hydroponics can be achieved
simply using a top-up system. You can use computerized dosing units
that maintain constant EC and PH by periodically topping up your
reservoir with fresh water and re-dosing with fresh nutrients but these
are very expensive and only really viable in a commercial environment.
However, a more simple, hobbyist method of auto top-up is a gravity
top-up system.
Gravity top up
To make life easier, place a second reservoir slightly higher than the first with a float valve in your main reservoir so it will be topped off when the
float valve opens. Fill your 2nd top up reservoir with half-strength
nutrient solution without any additives.
This will maintain a nearly constant EC level after each feed cycle instead
of being constantly diluted by topping off with only water. All recirculating systems should be refreshed with fresh water and fresh
nutrients at least every 14 days in growth and every 7 days in bloom.
You can also extend the time between needing to top up your run to
waste system using the gravity top-up reservoir system, but you should
fill your top-up reservoir with full strength nutrients that are pH
balanced.
Run To Waste
The run-off nutrients from this type of system are pumped directly
down the drain after irrigating your crop.
Your plants only ever receive perfectly balanced nutrients without ever
being diluted.
It is more expensive because you use a lot more nutrients but it's a
guaranteed method for high-quality flower production because no
waste 8 solution is returned to dilute your perfectly mixed nutrient solution after each irrigation.
Advantages of this method are that your plants always receive perfectly
balanced nutrition and your pH and EC should remain within perfect range, as long as you have a lid and no evaporation occurs.
Disadvantages include the cost of water and nutrients because your
runoff waste is sent directly to the drain.
Solutions
A better method of running a run to waste system is to have 2
reservoirs: 1 for fresh nutrient mix and one for runoff.
When your fresh nutrient reservoir is almost empty, you can accurately
measure the amount of solution that has been returned to the 2nd
reservoir, refill and redose accurately, and then either use it as your
nutrient reservoir for the following cycle or use it to grow leafy greens or
to water your garden.
Running a recirculating system is more of a challenge but can be more
rewarding because running your system for the first 2 weeks will usually
teach you a lot about how well your environment is doing.
For example, in an excessively hot room, your nutrient solution will lose
a high percentage of water through evaporation. This will result in your
nutrients condensing and your EC climbing and due to the higher
concentration of nutrients, your PH will drop.
If you are constantly topping up with water without the need to add
nutrients, your environment is too hot and your plants are only uptaking
water to combat the excessive heat.
Part 2: Supercharged Hydroponics - Morganics
Mineral feeds are more available than some organic substances that need to be broken down by microbes into simpler forms before they
can be absorbed by the plants.
But some organic substances pass through the roots very easily and can
be used to supercharge availability of mineral feeds.
Chelation
Chelation is an essential process for cannabis to be able to absorb and
utilise micronutrients.
The simplest way to explain this is to first understand that a proportion
of the micronutrients needed for healthy plant growth are actually
metals: Iron(fe), Copper (Cu), Zinc (Zn) & Manganese (Mn) and that these
need to be dissolved into plant-available ions before plants can make
use of them.
If these ions react with oxygen, they become oxidized and unavailable to
the plants.
At certain PH levels, they can also become sticky to other metals and if they are attracted to another metal ion, they combine and become too
heavy to be suspended in solution and precipitate, becoming
unavailable to the plant.
If you have added chelating agents to your hydroponic solution you are
chelating the minerals. The word chelate means ‘to grab’, ‘to (hold)’. This
means that your minerals are coated in an organic claw and this stops
them from reacting with each other and becoming unavailable. The
chelate also aids uptake because of its ability to pass through the root membrane very easily.
Nutrients and Feeding
The actual art of hydroponics is mastering your nutrient mixes and
being on top of everything, knowing all your inputs and outputs are
balanced, especially when running a recirculating system.
Mixing Nutrients
Whether you use liquid nutrients or powder, the process is pretty much
the same except you will need a set of digital scales to weigh powdered
nutrients.
I use Titan Hydro nutrients because their biostimulants are very high quality, their base nutrient ratio promotes terpene production, and using biostimulants enables lower concentrations of mineral feeds
Grow Recipe
Bloom Recipe
BiostimulantsBiostimulants are organic extracts that stimulate accelerated growth
and are catalysts for other higher plant functions as well as delivering an
array of beneficial trace minerals. There are many types of plant extracts that can be classed as a biostimulant but the most profound
are listed below.
The addition of these organic ingredients to a nutrient solution results in
a noticeable increase in health which stimulates increased growth rates.
Using biostimulants increases the availability of your nutrients, increasing uptake and adding trace elements to your recipe. Some of these could be catalysts or building blocks for complex terpenes.
I used to buy various liquid products from different brands but I prefer
these dry feeds, less plastic, eco-packaging, great results.
Chel8(Fulvic acid)
A chelating agent that increases uptake, increases drought resistance
and aids terpene production. It is a filtered extract of humic acid. It is a
very small molecule and can easily pass through leaf pores to deliver a
fast injection of nutrients by foliar feeding with it at 0.1g/L + CalMag
during veg or with PEAK during early bloom.
H89(Humic Acid Complex)
Derived from Jurassic decomposed trees, a byproduct of microbes, contains carbon, humic acid and 10% potassium. Chelates just like fulvic
acid does but also contains carbon and an array of trace minerals.
Its main advantage is it improves the soil or coir structure and helps
hold onto nutrients. If you filter humic acid, you get fulvic acid and
humates. H89 also contains 10% potassium.
Aktiv8(Kelp)
Ascophyllum nodosum is a very interesting plant that exists clung to
rocks in cold rough waters, withstanding damage from wind, waves and
cold. The 11 species also possesses survival gene triggers which produce
compounds to help heal wounds or protect from cold. It "also contains
Sulfated algal polysaccharides, which are a class of bioactive compounds
in algae that promote plant growth.
Extracts of kelp contain cytokines and plant beneficial organic acids
resulting in increased nutrient uptake, increased nutrient efficiency, increased resistance to abiotic pressure".( Fry et al., 1993 ; Paulert et al., 2009 ; Shukla et al., 2016 )
They say it way better than me, but Kelp is nothing short of adrenaline
for plants!
Bloom Boosters
During peak bloom, which for indica strains is between day 28 and 45
plants need more potassium and phosphorus.
We can’t add this elevated amount to the main feeds because they
would have overdosed on potassium and phosphorus so we use
separate products designed to deliver the correct ratio of both.
Many brands are available which are usually just potassium and
phosphorus. I use PEAK which contains added biostimulants and
chelating agents and amino acids which drive maximum uptake.
PEAK Bloom Booster with Amino acids
I only use it a couple of times throughout bloom, a small amount goes a
long way to giving the flowers that extra boost just when they need it, increasing the ratio of P and K to the Ca and Mg in the nutrient solution
triggers an impressive response.
I also like to foliar spray this product at 0.3g/L twice during the first week
of bloom when the plants are still being fed with grow feed until day 8.
Use whatever PK you usually use but you need to add biostimulants to
make it as effective.
Supercharged Uptake
Inoculating with beneficial bacteria and fungi while potting up or
transplanting protects roots, helps break down your organic
biostimulants and supercharge growth rates while protecting your
plants from any fungal infections.
I use a product called Mycorrmax from TNC (the nutrient company). They have soluble versions for hydroponics and soil.
SummaryPlants don’t need soil, they simply need support while they develop.
If you feed them mineral feeds and add biostimulants, your plants will grow at an alarming rate because in soil plants divide their energy
equally between producing long root systems to find new food sources
and these food sources are only readily available within a tight range of environmental conditions.
Too hot, too cold, or too dry and the microbes aren't active enough to
supply the required amount of nutrients needed for the plants to reach
their genetic potential, especially in high light gardens where the plants
demand a nutrient uptake constantly.
As long as you can manage your nutrient reservoir properly and
manage your indoor environment you will be addicted to the growth
rates achievable in a finely tuned hydroponic garden. Just remember to
keep notes so you know which tweaks to the recipe work in your
situation with your chosen strains.
Running a hydroponic system with added biostimulants is how to get the best of both worlds. Your crop receives perfectly balanced, highly
oxygenated nutrients regularly as well as all the trace minerals and
microbes they would benefit from in a soil garden.
I have shared my preferred choice of nutrients in this guide so I can
provide an easy to follow recipe if you want to follow my lead, but any
brand of nutrients will work. I would simply suggest that you give
powdered feeds a try, you will be doing your garden a favour and
helping reduce your carbon footprint and plastic.
About SeedsmanWe have been selling cannabis seeds online since 2003 and are considered one of the most trustworthy and reliable online seedbanks in the world. Our company
has evolved significantly over the past decade.
We sell our own brand of cannabis seeds - Seedsman, but also stock 1500 strains
from over 65 seedbanks from every corner of the globe. Not only do we have one
of the most comprehensive libraries of cannabis seeds in the world, we now offer
a diverse range of cannabis related goods for you to enjoy including storage
products, clothing and books. We pride ourselves on our customer service and
you should expect to receive a reply to any email you send us in less than 24 hours
(except over the weekend and in exceptional circumstances).
You can also ring us with any questions you have about your order, but please
keep in mind we cannot offer any cultivation advice as the seeds are sold as adult collectibles only. Cannabis Seeds are sold in countries where it is illegal to gflex-grid them for genetic preservation purposes. If you would like to find out more please visit our About Us page and check our Legal Disclaimer.
Our seeds are sent out worldwide using discreet & express delivery services. For further details please visit our Shipping Information page.