HYDROPONICGROW GUIDE

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.

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