Hope this helps the link issue
all you need to know about coco and a diy coco buffer recipe
the link didn't work. so i copy & pasted a cached version to allow it to be viewed.
Analysis of a Coco Coir Sample
All figures refer to ppm (mg/L)
S (Sulphate)
1978
P (Phosphorous)
126
K (Potassium)
3700
Na (Sodium)
2022
Ca (Calcium)
119
Mg (Magnesium)
104
Cu (Copper)
Zn (Zinc)
3.2
Mn (Manganese)
3.8
Fe (Iron)
12.2
B (Boron)
7
Cl (chloride)
3498
Take a close look at the elemental analysis of our coco substrate product. I would point out that this was a compressed product from Holland (originally deriving from Sri Lanka) which was tested after questions were raised as to why the product was seemingly killing plants.
You will note extreme levels of sodium and chloride or sodium chloride (NaCl or common salt). That is 2022ppm of sodium and 3498ppm of chloride. That is 2022mg (20.22grams) of sodium and 3498mg (34.98grams) of chloride Given that even 200 -300ppm of NaCl is dangerously high to many plants, the sodium chloride levels in this product were extreme and it resulted in disaster.
So another important factor that needs to be addressed - untreated coco coir can contain high levels of sodium chloride (salt). Try to remember that coconut palms grow well in areas of high salinity. This means they uptake a lot of salt from their environment. Plants that are salt tolerant are able to uptake salt and then displace it into areas of the plant where it does the least harm. Seemingly, much of the salt is displaced into the coir of the coconut palm (the very thing we use as a hydroponic medium). Factors that will influence the NaCl levels in any coir product include the treatment it has received prior to sale and how far inland the coconut palms are grown (the further inland the less salinity/salt in the soil/sand and hence the less salt that is uptaken by the coconut palm).
Other than this you will note 3700ppm of Potassium and 1978ppm of sulphate. This tells us that there are high levels of potassium and sulphate that are naturally present in coir products.
Due to these factors, in Integral Hydroponics, I recommended that, ideally, growers should purchase buffered coir products and use coco coir nutrients when growing in coco substrate.
OK – so the buffered products tend to cost more. Those cheap compressed blocks that you can buy from gardening centres etc are just as good as premium grade buffered coco coir – or at least that’s what’s asserted by some.
Some of the cheaper compressed products may perform well with a good flushing prior to use (hopefully, if very high levels of NaCl are present you may be able to flush it out with water before the salt detrimentally affects plant health) but the fact is, that buffered and hydrated products in almost all cases are superior to unbuffered products and there are very good (scientific) reasons for this.
Coir needs to be buffered to offset the NaCl levels, to compensate for natural potassium and sulphate levels and to charge (prepare) the medium with the right ions to facilitate adequate cation exchange capacity (CEC) within the medium.
Signs of toxicity (high levels of NaCl in coir substrate)
Slow/stunted growth
Unhealthy plants
Yellowing
Burning
Rusting on edges of leaves
Rust spots on leaves
Flushing and Buffering compressed coir blocks
Let’s now talk about how to use (prep) a cheap compressed or uncompressed (non buffered) product that you buy through garden centres. That is, how to buffer the compressed product correctly, in the same way that some coir substrate producers/on sellers do (e.g. CANNA,
Atami B’cuzz etc).
It’s important to note that some coir products available through garden centres etc may be sold as soils/potting mixes with NPK added – avoid the use of these products; they aren’t developed for hydroponics. Besides this, the compressed blocks are cheaper and you’re now about to learn how to turn these into high quality buffered hydroponic coir substrates.
Here’s our buffer formula used to pre-treat and hydrate compressed coir blocks.
Coco Substrate Buffer
(Used for preparing non-buffered coco substrates such as compressed coco blocks)
Calcium Nitrate 290 g/l
Magnesium Nitrate 280 g/l
Magnesium Sulphate 10 g/l
Ferric EDTA 2 g/l
Make 1L by beginning with 500ml of RO (demineralised) water. Add ingredients one at a time, dissolving each ingredient before adding the next. When all ingredients have been added, top up to 1000ml (1L) with RO water.
What I recommend you do is hydrate the coir blocks in mains (tap) water. That is, fill a bucket or tub with mains water. Measure the EC of the mains water before adding the compressed coir block/s. Let’s say it’s EC 1.0 for arguments sake. Add the compressed coir block and allow it to expand. Stir the water and coco substrate around and then measure the EC again. You’ll no doubt find the EC is now much higher. OK, now run mains water through the coir (you may find a bucket with holes and mesh at the base helps here). Run the mains water through (flush) the coir until the water that has passed through the coir (runoff) is no more than EC 1.0 - 1.2. I.e. Original mains water EC ideally matches that of the runoff.
Now fill up a bucket with demineralised (RO) water and dilute the buffer concentrate to 1.4 EC (700ppm). Place the hydrated/expanded and water flushed coir into the diluted buffer solution and leave to soak for at least one hour.
After one hour or more, take out the now buffered coir and squeeze out the excess fluids so the coco substrate is not saturated/water logged. You may find drying it in the sun for a while helps. .
Ready to go – you now have a high quality buffered coir product at a fraction of the cost that you would pay for similar products through stores. I’d also recommend that you mix the coir with perlite. 60% coir to 40% perlite when using it as a run –to-waste medium.
Tip: Many of the compressed coco blocks that are purchased through gardening centres are (when uncompressed) coco powder. If this is the case, look for varying grades of coco substrate, working from fine to larger fibres and mix them into a single product to increase air porosity within the media. The ideal coir particle size is 0.5 – 4mm.
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Optimum Coir Particle Size for Optimum Yields
Research has demonstrated that optimum growth rates will be achieved in “medium particle sized” (0.5 – 4mm) coco substrate. The research, conducted on tomato plants and seedlings, measured germination and growth rates in coarse particle (greater than 4mm), medium particle (0.5 – 4mm), fine particles (less than 0.5mm), and raw coco peat (unseived material) with findings that the highest numbers of leaves and growth rates were achieved in medium particle sized coir substrate.
Quote: “Tomato plants grown in coco peat with medium sized particles, showed significantly higher plant heights when compared to tomato plants grown in coco peat with other particle sizes.” 1
1. Effect of Particle Size of Coco Peat for Greenhouse Tomatoes: H.K.M.S
Kumarasinghe. Department of Crop Science, Faculty of Agriculture, University of Rahuna
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Mixing Coir and other Media
Perlite
Each particle of perlite consists of tiny air cells that provide for a large surface area. Because of the shape of perlite, large air gaps form between the particles. This means there is plenty of oxygen available to the root system.
Perlite doesn’t compact and because of this maintains an ideal balance of oxygen and water (oxygen moisture ratio).
Perlite is very tolerant to overwatering which makes it very forgiving medium. Because of its nature, perlite allows excess water to drain off and provides an air ratio of approximately 40- 45%.
Perlite, like coco, has thermal insulation qualities, which provides the root zone with a high degree of security against heat.
Perlite is a very cost effective medium. It is about half the price of expanded clay.
Lab Analysis: Comparison of Perlite and Coco Samples
Perlite
Air Porosity: 40%
CEC: 5.0
Water Holding: 28.9
Coco (6mm particle size)
Air Porosity: 20%
CEC: approx 63.1
Water Holding: 66.5
Buffered Coco (Medium Particle Size Sample)
Particle Sizes:
MATERIAL > 2mm % 7.5
MATERIAL 1.00 - 2.00 mm % 25
MATERIAL 0.85 - 1.00 mm % 27.5
MATERIAL 0.30 - 0.85 mm % 15
MATERIAL 0.075 - 0.30 mm % 22.5
MATERIAL < 0.075mm % 2.5
CATION EXCHANGE CAPACITY 56.69
Water Holding: 51
Air Porosity: 30%
Re Air porosity measurements
There are two methods that are commonly used for measuring Air Filled Porosity (AFP) in the coir. These are:
The European EN-method: Loose coir (no compression) is saturated with water and allowed free drainage for 24hrs. AFP is then measured. A quality buffered product such as
Atami coir measures at approximately 35 – 40% AFP under this method.
The Dutch BLGG method: Coir is slightly compressed in a container and saturated with water where it is then allowed free drainage for 24hrs.
Atami buffered coir measures at 20 – 25% AFP under this method.
Author’s note: Optimum AFP = 30%. Realistically, even the highest quality coco coir may become saturated and compressed over a 10 or so week growing cycle (represented AFP being the Dutch BLGG method at 20 – 25%). For this reason, I recommend mixing perlite with coir at a 60 - 70 (% coco substrate - 30 -40 (% perlite). This ensures optimum AFP at 30% throughout the crop cycle. I.e. Perlite has approximately 40- 45% AFP and will increase AFP in the coir.
Clay Balls/Expanded Clay (e.g. Hydroton) and Coco Substrate
I’ve noticed on internet forums that many growers speak of using expanded clay instead of perlite when working with coco substrate and RTW growing.
Other than this, many growers seemingly use expanded clay at the base of the pots to allow for “better drainage” (not a bad idea). That is, they line the base of their pots with expanded clay to perhaps two to three inches and then fill the pots with a mixture of coco substrate and expanded clay.
I personally can’t see a problem with using expanded clay with coco substrate other than perlite has a higher air capacity than expanded clay (45% versus approx 30 - 35%). Other than this expanded clay offers the roots less security than perlite and is an effective conductor of heat.
Coco Nutrition
We have seen that coco substrate contains naturally high levels of potassium (K) and therefore a nutrient formulated for coir will have lower potassium (K) levels than a standard nutrient. Other than this we have also seen that coir naturally contains sulphates and therefore a nutrient developed for coir would contain less S than a standard nutrient (or so this should be the case – at least one “hydro” manufacturer has been known to pass off standard nutrients labelled as coco formulations).
Some years ago I had one European company’s formulas for coco and standard bloom analysed. The company makes a single product for coco (one formula used for both grow and bloom) and therefore it is a one size fits all product. Largely however, it is formulated as a bloom product. This was likely due to Dutch growing methodologies where the growth cycle tends to be very short before the light hours are switched down to 12/12 to induce flowerset (i.e. multiples of small plants per square metre). Other than this, you can see our buffer formula (a reverse engineered copy of this company’s formula) contains high degrees of calcium nitrate and magnesium nitrate, meaning a high degree of NO3 Nitrogen and Ca and Mg is present in the coco medium to help facilitate growth in the early veg stages (the extra Ca, N and Mg will be quickly depleted by vigourously growing plants and it is recommended that you use a coco grow formulation if vegging for an extended period of time).
OK – so let’s now have a look at the two analyses (a side by side comparison of this company's bloom standard against their coco –bloom- formulation) and check what the differences are.
SAMPLE
Prod X
Prod X
Prod X
Prod X
NAME
FLOWER A
FLOWER B
COCO A
COCO B
SERIAL #
051167
051168
051147
051148
ELEMENT
NH4N (mg/L)
128.3
2158
117
1184
NO3N (mg/L)
43080
10642
42200
6780
S (mg/L)
45.55
11740
47.1
7930
P (mg/L)
15.96
17280
14.4
16190
K (mg/L)
37830
26070
6880
16780
Na (mg/L)
55.2
136.1
39.8
122.3
Ca (mg/L)
32840
586
53600
620
Mg (mg/L)
225.7
10180
7470
12310
Cu (mg/L)
1.32
11.24
1.2
9.4
Zn (mg/L)
0.51
59.6
1
69.2
Mn (mg/L)
0.59
121.4
3.2
122.9
Fe (mg/L)
190.6
4.19
199.5
2.1
B (mg/L)
< 0.5
60.9
0.9
63.4
Cl (mg/L)
12.5
32.85
13.4
34.3
pH
2.92
2.97
2.8
3.04
COND. (dS/m)
141.5
92.7
103.4
82
Look closely at the numbers. You will find they are quite different and that the theory (what I have been saying) matches the formulation. It is clear to see that the coco formula contains far less potassium (K) than the company’s standard bloom formula, less sulphate, more calcium, more magnesium and so on. That is, the formulas differ vastly. One is formulated for an inert medium (standard bloom) and one is formulated for a hydroponic medium that contains high levels of potassium and sulphates (i.e. coco substrate).
Potassium competes with magnesium and calcium and therefore both magnesium and calcium levels have been raised in this formulation to compensate for natural potassium levels within the media. Other than this, due to the cation exchange properties of coir, some calcium is immobilized (held) and higher levels of Ca are required in formulation (along with Ca Mg buffering prior to use).
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Understanding Cation Exchange Capacity (CEC) and Coir
CEC relates to a soils/substrates ability to attract, retain, and exchange cation elements.
Cation elements are elements with positive electrical charges; these being potassium (K+), ammonium (NH4+), magnesium ( Mg++), calcium (Ca++), zinc (Zn+), manganese (Mn++), iron (Fe++), copper (Cu+) and hydrogen (H+). While hydrogen isn’t a nutrient it affects the degree of acidity (pH) of a substrate and, for this reason, is important.
Some nutrients have negative electrical charges. These are called anions and include nitrate (NO3 N), phosphate, sulfate, borate, and molybdate.
The word "ion" (as in cat –ion and an – ion) simply means a charged particle; a positive charge is attracted to a negative charge and vice-versa. This means both positive and negative charged nutrients/elements form a symbiotic relationship and are available for uptake.
High CEC values indicate that a soil or substrate has a greater capacity to hold cations and where there is high CEC there is a large nutrient reserve.
Coco substrate has high CEC.
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Actually, let me further assert the point now that soil and coco are very different mediums and need to be handled very differently where nutrition is concerned (among other things). Here is an analysis of the same company’s soil flower formula – this analysis was conducted in 2003 in Australia (it may differ from the European formulation but I suspect not). This is a single part formula, whereas our coco formula is a two part A and B set.
Element
Flower
Nitrate N (g/L)
22.0
Ammonium N (g/L)
5.0
Urea N (g/L)
6.1
Phosphate P (g/L)
9.6
Potassium (g/L)
35.3
Calcium (ppm)
137
Magnesium (g/L)
5.94
Iron (ppm)
115
Copper (ppm)
13
Manganese (ppm)
123
Zinc (ppm)
62
Sulphate S (g/L)
6.86
Sodium (ppm)
456
Chloride (ppm)
815
EC (mS cm-1)
105.0
pH
1.74
It’s worth pointing out that this analysis is in grams per litre, so to achieve mg/L you simply need to understand that 1000mg (or 1000ppm) equals 1 gram. Therefore 22.0grams Nitrate in the flower formula equals 22,000mg Nitrate. Other than this, elements found in lower concentrations are listed in ppm. 1 ppm equals 1mg/L.
This is a fairly simple fertiliser blend which is about 22% solids. EC is high and pH is low because it is made with nitric acid. Relative to other major nutrients, calcium is quite low. As such it is not suited to fertigation (i.e. intermittent drip feed as in run-to-waste systems), but is suitable for less frequent, heavy applications (as you would typically apply in soils).
Now compare the soil bloom numbers to the coco formulation – you’ll note that they are extremely different.
You will also note the product contains urea. Urea, CO(NH2)2, doesn’t supply any ammonium nitrogen (NH4 Nitrogen) or nitrate nitrogen (NO3 Nitrogen) and is completely different form of nitrogen to both NH4 N and NO3 N . Urea is widely used in soil applications but is seldomly found in hydroponic formulations.
You will note that the soil flower formula contains 35.3 grams of potassium (or elemental K) which equates to 35,300mg/L of potassium (elemental K). Now compare this to our coco formula and note that it contains 23660mg/L when we add the potassium mg/L in part A and B. Now compare the sulphate levels in the two formulas. In the soil formula there is 68,600mg/L of elemental S, whereas in the coco formula we have 7977 mg/L of S. Now, compare the calcium levels in each formula. In the coco we have 54220mg/L while in the soil formula we 137mg/L.
Compare all the numbers if you like and you will find massive differences between a nutrient that has been formulated for soil against one that has been formulated for coco. I hope this clarifies my point that coco and soil are extremely different mediums and require very different treatments. Coco is coco and soil is soil - let's not get them confused.
We’ll talk about how to make these soil formulas later in the book when we discuss the various approaches to optimising yields in soils. There are many ways to skin this cat and we’ll discuss this subject in depth and provide you with several formulations (some of which are manufacturer direct).
Ok, so here’s how to make our own coco nutrient based on the European formulation. It is a product I’ve worked with many times and a product I’ve always considered a good coco nutrient, hence providing the formula in the book. …… (Section deleted for the website)
pH measurements in Coir
Coco coir buffers pH in the range of 5.5 – 7. However bacterial activity and nutrient quality can have an impact on pH stability within the media.
Another misconception I have commonly encountered is that by measuring the run off (waste) in coir it is possible to measure the pH of the medium. Let’s quickly dispel with this myth. Coir media will retain some elements and release others (a process of preferential retention of cations) based on the uptake needs of plants and the prevailing conditions of/within the media.
Because of this, measuring the run off (waste) will not reflect the pH within the coir medium (i.e. the rhizosphere environment of the plants).
The correct way to measure pH, in coco substrate, is to take samples of the media from around the root zone. These samples are then added to distilled water at a 5:1 ratio (5 parts distilled water to 1 part media), then vigorously shaken or blended and tested with a pH meter. This method will provide you with the correct pH within the coir media (rhizosphere) environment.
Feed Regime
In Integral Hydroponics Edition 1 to 4, I recommended multiples of smaller feeds allowing for between 10 – 30 per cent run off. Technically, at least from a agricultural (science) perspective this is the recommended way of feeding.
If using RO (demineralised) water I would recommend a 20% run off (waste) regime.
If using mains (tap) water, I would recommend run off (waste) be maintained at 30 percent due to naturally present salts that are often found in tap water supplies. Elements such iron (Fe), magnesium (Mg), calcium (Ca) and sodium (Na) and chloride (Cl) which combined form common salt (NaCl). Sodium and Chloride normally occur together and are not taken up to any degree by most plants, especially sodium; therefore, they tend to accumulate if present in significant amounts.
In some cases tap water supplies can contain high EC/ppm levels of these salts (ions) and this can detrimentally affect the growing medium. Therefore, in order to circumvent any problems that can occur as a result of this, I recommend a higher waste percentage if using mains water than if you were growing with RO or rain water.
I should also add some information now, regarding feed regimes in coco substrate.
Since writing Integral Hydroponics (originally published in 2002) I have seen growers using all manner of feeding techniques and achieving extremely good results. One friend - a long time and very advanced grower - who had been using a wide channelled NFT system switched to coco coir and contrary to my advice began hand watering. I was somewhat perplexed by why he would go this way but I’ve always preached KISS (Keep It Simple Stupid) and was intrigued by his methods. For the next 10 or so weeks I watched closely as my friend Feral saturated his pots full of coir twice daily (during the lights on period) with a resultant approx 50 per cent run off on each feed.
“Mate, you’re over watering” I contended,” the medium is too saturated and you’re reducing the natural air porosity of the medium. (A quality coco substrate product will possess approximately 30 per cent air porosity, which is ideal for rhizosphere health).
“Yeah, but they look great and they’re growing faster than anything I’ve ever grown before”, he responded. To this I couldn’t argue; indeed, the plants were as healthy as any I’d seen and were growing at a rapid rate.
On his first grow he realised a 30 - 35 per cent increase in yield to what he had been achieving through his much touted (bells and whistles) wide channel NFT system. Of course, at this point he was sold and began switching all of his friends to coir substrate RTW growing (after years of promoting the wide channelled NFT system via internet forums to all who would listen).
The moral of the story is this. There are ideals where agricultural (scientific) principles are concerned. However, what I have learned (gained) from Feral and others is that coco substrate tends to be so forgiving, that whether you feed multiples of small feeds with 10 – 30 per cent waste (methodology correct) or whether the medium is hand watered and therefore more saturated, you will achieve great results.
Coco Substrate and Sciaradae (Fungus Gnat, Shore Fly)
Because coco substrate is organic it slowly decomposes in its wet state. This causes the release of nitrates as part of the decomposition process. There’s not much wrong with this as long as the nitrate release is minimal (which it is). However, this nitrate release is what attracts Sciaradae (fungus gnat). Sciaradae are commonly found in organic composting material. Therefore, coco substrate can be a highly effective attractive media for Sciaradae.
Sciaradae, shore flies or fungus gnats are often present in conjunction with pythium. Fungus gnats feed on rotting vegetation and other decomposing organic material. It is not certain whether fungus gnats are drawn to crops that are suffering pythium because of the presence of decomposing organic material or whether fungus gnat is responsible for introducing the pythium. It is more likely that the fungus gnats are attracted to rotting vegetation that is inhabited by pythium fungi (oospores). The gnat larvae (1-2mm white maggots with black heads) can live on a diet of pythium oospores before some of them mature into the flying stage (adults) and carry fungi to other crops. This means the presence of the fungus gnat could be a precursor to a pythium outbreak in your crop.
Other than this, Sciaradae larvae are laid by the adults in the growing medium and their food source largely consists of the roots of the plants and decomposing material.
Adult Sciaradae resemble tiny fruit flies. When they are put under a magnifier their wings can be seen to have, what look like, accentuated veins. Sciaridae have a life cycle of egg, larvae, puparium, and adult. While the adult flies will only live a few days, one female fly can lay as many as 200 eggs. The lifecycle from egg to adult can be estimated at 3-4 weeks. For this reason infestations occur at a rapid rate.
Sciaridae eggs are laid around the soil/media surface. These hatch into glossy, legless larvae with black heads. The larvae are equipped with a sharp pair of mandibles, which are used for sawing and rasping into the soft stems and roots of the plants.
Controlling Sciaradae
Pesticides: I have found that after using numerous approaches and products (biological and pesticide) the Permethrin based products (Coopex, Axe etc) are the most effective treatment for totally eradicating Sciaradae from the crop. Permethrin is non systemic and and degradates (neutralises) quickly which makes it ideal as it is not up taken by the plant in any way.
The product I typically work with is Coopex WP 250g/kg powder which comes in 25gram sachets. Coopex is manufactured by Bayer and is widely available in most countries. Mix one sachet to 10 litres, hand water (drench) the media and leave for an hour. After this, flush with pH adjusted nutrient and you are ready to go.
Yellow sticky traps hung at media height will trap the adult Sciaradae. This will help reduce numbers. More importantly it will allow you to monitor whether Sciaridae are present in the growing environment.
Tip (About Sciaradae)
Look out for:
Signs of the pest through the use of yellow sticky traps
Deformed leaves and generally unwell plants can indicate an infestation of Sciaradae
Recycling the Media
Coco substrate can be used in more than one crop cycle if it is prepared correctly prior to reuse.
The key here is in cleaning the media of dead root material (cellulose) and priming it with a buffer before reuse.
I have noticed on forums that many people speak of using Zyme (e.g. Cannazyme, Sensizyme) products for breaking down the dead root material. This is an area of concern due to the fact that while fungal cellulose enzymes are definitely effective at breaking down cellulose (after all, this is what they do in nature) the products sold through the hydro industry possibly/probably are inert. I.e. Devoid of enzymes.
There are serious question marks over the shelf life of liquid enzyme products. That’s not to say that enzymes are a bad thing -without a doubt they have a place in hydroponics/agriculture and can be potentially beneficial to plant health. However, as with friendly bacteria, the sale of these products through the “hydro” industry is, often, greatly over simplified (talked up and hyped). That is, the enzymes are contained in a liquid state and because of this they may or may not be present/active when they are purchased off the shelf. Other than this, enzymes aren’t so dissimilar to bacteria in that they need a complimentary environment in which to remain stable and work. However, by their very nature enzymes are unstable and herein lies the problem. I.e. If I make a liquid concentrate and then put it on a shelf for months at a time will there be enzymes present or not when that product is purchased? Probably not....
One producer who sells a Zyme product claims they have tested their competitors Zyme formulas and found that they were (to quote) “junk”. They go onto say, “Enzymes have a shelf life. They can expire in their bottles.” Other than this they claim to have purchased five different companies formulas (from several locations), including their own, and after testing their competitors’ products they were found to be “inert, meaning there was no biological activity left in them.” Of course, their formula, when tested, came through with flying colours.
Back to reality and the science – let’s avoid the scam factor that is too often proliferated by a few to so many.
So, what is a reliable/effective means of recycling the media?
Trichoderma Harzianum (T.harzianum)
A lot of research has been done with a mould called Trichoderma harzianum with very positive findings. Trichoderma harzianum is a friendly mould that colonises the rhizosphere and competes with other organisms.
Trichoderma is parasitic to other moulds such as pythium, fusarium and phytopthora. That is, Trichoderma protects the plants from these organisms, all of which are capable of destroying your crop.
Trichoderma enhances plant growth due to its ability to produce beneficial enzyme complexes. Trichoderma can also survive for long periods in a host, and needs only minimal carbon levels to ensure its subsistence. Trichoderma also stimulates root growth while breaking down cellulose (dead root matter etc) and therefore is an extremely effective and reliable way to treat media for reuse.
Coco substrate, more so than any other hydroponic medium, provides an ideal environment for friendly moulds and friendly bacteria.
To recycle the media effectively, remove as much dead root matter as you can by first cleaning, washing and sieving the media and then apply a treatment of T.harzianum to the coco substrate. Maintain its use for several weeks (better yet – throughout the entire crop cycle) and watch your plants grow.
Which brings us to our next point – the use of ‘friendlies’ in coco substrate.
Understanding Friendly Bacteria
This is an area which is largely misunderstood by many indoor growers so I thought I’d expand on the science of friendly bacteria in hydroponics.
Friendly bacteria protect the plant from water born pathogens such as pythium and fusarium. Other than this, they help in nutrient uptake and produce plant growth promoting substances. They can also protect plant surfaces from attacks by pathogenic microbes through direct competitive effects and production of anti pathogenic compounds.
For these reasons, the use of friendly bacteria in hydroponic growing systems has advantages over sterilisation (i.e. the use of monochloramine or
hydrogen peroxide etc).
The Science of Friendly Bacteria
In nature non-harmful or beneficial organisms naturally combat harmful pathogens such as pythium and fusarium. Generally speaking non-harmful bacteria numbers explode at a faster rate than harmful bio organisms. As the non harmful bacteria numbers explode they form biomass around the rhizosphere of the plant. This biomass prevents harmful organisms entering the rhizosphere of the plant.
In addition to this, some bacteria are beneficial to plant growth. These bacteria are commonly known as plant growth stimulating bacteria (PGSB).
In nature, friendly bacteria (or friendly moulds) are naturally found in environments that are able to support them (bio-diverse environments). A bio-diverse environment ensures that the microorganisms survive and thrive. On the other hand, if the environment is lacking and is not able to support them, the bacteria will die out very quickly.
For instance, at least one “hydro” company promotes the use of mycorrhizae fungi in hydroponic growing systems and sells products to this effect. However, it is important to note that mycorrhizae fungi cannot colonise and sustain biomass in high phosphorous (P) environments (i.e. hydroponic systems) and therefore their use and viability/effectiveness in hydroponic settings is questionable. That is, the mycorrhizae fungi cannot colonise and sustain biomass in a hydroponic growing system unless the nutrient has been formulated with low phosphorous levels to cater for colonisation of the fungi (this is not advisable because the nutrient would then be lacking in phosphorous).
Mycorrhizae fungi are suitable for low phosphorous environments and are ideal for soil amendments where regular P fertilization isn’t taking place.
“In a second experiment, two nutrient media, modified Long Ashton and modified Knop plus Hoagland medium were compared for culturing G. mosseae on T. aestivum. A significantly higher root dry weight was found for the mycorrhizal versus the non-mycorrhizal wheat plants in modified Long Ashton nutrient medium, which contained 10 µM P and an organic buffer. Modified Knop plus Hoagland nutrient medium contained a high P concentration (0.9 mM) and did not produce viable cultures of mycorrhizal colonisation….. This report describes a system for the viable culture of G. mosseae with different plant species where a high mycorrhizal colonisation rate was produced under conditions of a short culture period using intermittent aeration, a low concentration of P supply and an organic buffer.” 1
[End Quote]
1. H.-J. Hawkins and E. George (2004) Hydroponic culture of the mycorrhizal fungus Glomus mosseae with Linum usitatissimum L., Sorghum bicolor L. and Triticum aestivum L.
You can perhaps tell that the correct use of friendly bacteria can be a slippery slope and it is important to understand the science in order to ensure that a healthy rhizosphere environment is maintained through
Introducing the right bacteria into the growing system (and)
Ensuring there is a conducive environment to sustain and increase ‘biomass’ (bacteria numbers)
Friendly Bacteria Products
Liquid Vs Dry Friendly Bacteria Products – which are better?
Liquids
Let’s say I isolated some friendly bacteria – say a couple of types of bacillus – and they were isolated from yoghurt or soap by products. Let’s say I threw my bacillus in a bottle of fluid with some food (sugar and carbons). Then I put the bottle on a shelf for a month or two (or three or five). My bacillus might survive until their food ran out; then again something else might happen to them, such as they might survive in lower temperatures but die out very quickly at higher temperatures or they may survive in one pH but die out (or reduce in numbers) at another pH. There are just too many variables to consider and there are no guarantees that you are getting what you have paid for in the case of many of the “hydro” industries liquid friendly bacterial products.
Author’s note: There have been breakthroughs in research and at least one liquid product that is sold through the agricultural sector has stabilised bacteria contained within the fluid. We’ll post updates on
www.integralhydro.com
Dry Bacteria Products
These products, for the most part, are far more reliable than most of the liquid products (sold through the “hydro” retail industry) due to the ability for bacterial spores to survive long term in a dry, suspended state (bacillus spores, for instance, can survive for approximately 2 years if stored at room temperature – 20 - 250 C). Effectively the spores are attached to either a sugar or a carbon base (or both) where they remain suspended until they come into contact with water (i.e. placed in the nutrient tank). The shelf life of these products is, therefore, far more reliable than that of their liquid equivalents. These products are best stored in an air tight bag in the fridge.
Sustaining ‘Biomass’ (Bacteria numbers)
The food source for friendly bacteria is sugars and carbons. Create an environment that is rich in these components and you will create a dynamic environment for friendly bacteria.
Fulvic Acid
Where friendly bacteria are concerned humates (e.g. humic acid and fulvic acid) are an extremely effective food source. Humates are carbons – elements of ancient compost that formed over millions of years through the interaction of organic material and microbial action – and, therefore, their presence (along with other factors) in the growing system will ensure a rich environment in which friendly bacteria numbers will explode.
Fulvic acid is the most important humate bio-extract where hydroponics is concerned. It is water soluble and readily available for plant uptake.
Other than creating a dynamic environment for friendly bacteria, fulvic acid aids greatly in nutrient uptake and translocation within the plant. For this reason it should always be used in conjunction with a balanced nutritional program.
Fulvic Acid Benefits:
Enhances cell growth
Increases nutrient uptake
Increases nutrient transportation
Increases silica absorption
Stimulates plant immune system
Creates a dynamic environment for friendly bacteria
Humic Acid
Humic acid is less suitable for hydroponic systems. However, humic acid is suitable for soil growing and its use in soils will prove beneficial for rhizosphere microbial interaction and nutrient uptake.
Sugars
Other than humates (i.e. carbons) sugars are also the food source for friendly bacteria. Because of this, products containing molasses (e.g. some organic stimulants) and other sugars can be beneficial in the growing system.
Cautions when using Friendly Bacteria
If you are adding friendlies to chlorinated water supplies (i.e. mains water), there is every chance (depending on the level of chlorine) that the chlorine is killing a good many of the beneficial microorganisms. Ideally you will have a secondary holding tank where you can leave your tap water exposed to air for 24 hours prior to it going into your system. This will ensure the water is chlorine free (the chlorine dissipates) by the time you introduce the friendlies.
On this note, sterilising agents (e.g. monochloramine or
hydrogen peroxide) should never be used in conjunction with friendly bacteria.
Beneficial Microbes for Hydroponics
Just some of the beneficial microbes for hydroponics are:
Trichoderma harzianum, Bacillus Subtillus, Pseudomonas and Azopirillum.
You can possibly buy dry friendly bacteria products through your local agricultural supply store or through garden centres. Where possible, try to purchase in bulk to save money. In some cases you may even be able to purchase manufacture direct. You can also purchase bacillus and trichoderma products through
www.integralhydro.com (No hype! We bring you the science)..... Coming Soon..
Grow well....
