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. Thats 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 arent 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 lets 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 Id 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.
- 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
Lets say I isolated some friendly bacteria say a couple of types of bacillus and they were isolated from yogurt or soap by products. Lets 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.
Authors 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.
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.
Grow well....
