For decades, conventional grow wisdom dictated that organic nutrients could not be successfully used in hydroponic systems. In reality, this is certainly not the case! In this article, we’ll talk about the different ways it can be achieved – as well as touching on the controversy the movement is currently causing.
Why is Organic Hydro a Controversial Topic?
The National Organic Standards Board, an advisory committee to the US Department of Agriculture, voted in 2017 to allow organic certification for some hydroponic and aquaponic crops. This is a landmark step that appears generally positive, but has nonetheless angered traditional organic farmers who believe that organic farming depends primarily on healthy, living soil as its basis.
While there may be some basis for this argument, the emergence of organic hydroponics seems less of threat to traditional organic farmers than to conventional hydroponic farming itself. In fact, reports suggest that increasing numbers of conventional farmers would like to (and are beginning to) incorporate organic techniques into their operations.
That more farmers haven’t so far is arguably due to lack of funding, inexperience and lack of confidence in the comparative profitability and reliability of organics. It’s very unlikely that it’s borne of an inherent, unshakable preference for chemical fertilizers and pesticides. As organic techniques grow in popularity (and costs for equipment potentially drop), these barriers will continue to fall.
Thus, a system that can combine the speed, quantity and consistency of hydroponic production with the quality and potential environmental advantages of organic production should ultimately prove desirable to many. Whether organic hydroponic systems live up to those claims is hard to quantify at present as relatively few cannabis growers use them; however, among proponents, results appear to be very encouraging.
Organic Compounds Can Clog Hydro Systems
The conventional grow wisdom is not without some basis in fact. Many organic nutrients are not fully soluble, and clog up systems with residual sediments. Furthermore, organic growing regimens involve the use of vast quantities of beneficial microbes, plus plenty of sugars (often in the form of thick, sticky molasses).
A week or two of putting all these insoluble, sticky substances into your system, and you could end up with thriving bacterial colonies feasting on thick layers of organic nutrients. These could end up clogging tanks, pumps, and drippers too, like bad cholesterol clogging up arteries!
These problems are not limited to strictly hydro systems. When using soil or soilless mixes with drip irrigation systems or other means of automated watering, you’re also usually limited to only using organic nutes that don’t clog up your system (or to dealing with the ongoing nightmare of trying to keep them clean).
Anaerobic Conditions Can Rapidly Arise
In recirculating tanks, build-up of nutrients and bacteria can rapidly reduce oxygen levels, like algal blooms do when too much agricultural runoff seeps into the water. It that situation, beneficial microbes can’t survive and pathogenic, anaerobic microbes begin to dominate. Of course, roots also require oxygen, and if they are deprived of it plant growth will quickly cease.
This problem is not limited to organic systems – conventional hydro systems can also get clogged up with roots, algae, bacteria and all kinds of organic gunk. But of course, it doesn’t go against the principles of conventional hydroponics to use chemicals to get rid of all organic matter. Needless to say, that’s impossible to do with organic hydro, as the whole concept depends on maintaining a healthy colony of microbes, and most cleaning chemicals will kill them all.
As we’ll see, adequate oxygenation is a fundamental aspect of maintaining a healthy organic hydroponic system – even more so than in conventional forms of hydro.
Organic Nutrient Availability in Hydro Systems
Another major difficulty when using organic nutrients in a hydroponic system (particularly a substrateless system) is ensuring that sufficient nutrients are available to the plant.
Hydroponic systems allow plants to take up water and nutrients at significantly increased rates compared to soil. This speeds up growth and yield and shortens overall harvest time. But it also requires nutrients to be constantly available at optimum concentrations. In conventional hydro, this is achieved by using mineral salts that the plant can immediately utilize.
Organic farming instead relies on the presence of microbial life to break down complex organic molecules into simpler forms. This process can take some time, so even if your nutes don’t clog up the tank and all other variables are good, the nutrients your plant needs to support that accelerated growth just may not be there in sufficient quantities.
This will likely lead to deficiencies and stunted growth as the plant takes up some nutrients and not others. This problem is not just limited to hydroponics – even in soil-based organic growing, providing sufficient nitrogen and certain other nutrients often presents difficulties. In practice, this has sometimes led to vegetable farmers supplementing their organic crops with inorganic nutrients.
So, anyone wishing to successfully implement fully-organic hydroponics must ensure that a rich microbial population is supported, so that the biological reactions necessary to feed the plants can happen at a fast enough rate. This, as we’ll explain now, is where using a biofilter comes into play!
The Importance of the Biofilter
The beating heart at the center of organic hydroponics is the biofilter. In general, a biofilter is a system that takes in large, complex organic molecules and breaks them down into simpler molecules, with the help of oxygen and biological catalysts (such as microbes!).
All organic hydroponics systems depend on the existence of a biofilter, based on microbial catalysts to break down the complex nutrients and deliver them to the plants. In essence, the biofilter is doing the job that soil usually does.
In systems that are based on the use of a substrate, the substrate beds themselves can act as the biofilter. This is true of many aquaponic systems – it just depends on providing enough surface area, oxygen and nutrients for thriving microbial life to develop.
Main Types of Organic Hydroponic Systems
There are various forms of organic hydroponic systems in use today. Arguably the best-known form of organic hydroponics is aquaponics, which we will describe in the next section. Then, very similar to aquaponics, we have vermiponics – which uses worms instead of fish to break down complex nutrients. Typically, soluble “worm tea” is made by steeping their castings in oxygenated water for several hours.
Another rather fascinating branch of organic hydroponics is amusingly known as “peeponics”. As the name implies, this system relies on the dissolved nutrients in human urine (pee!) to supply plants with food. As urine contains abundant nitrogen, phosphorus, potassium and sulphur, along with an array of trace minerals, it provides excellent nutrition for plants.
Peeponics is quite close in concept to bioponics, another main type of organic hydroponics that we shall discuss in more detail soon. Both rely on fully dissolved nutrients, and do not require an intermediary like fish or worms to break down complex molecules.
What Exactly Is Aquaponics?
Aquaponics is a method that’s been around for decades now, and has quite a solid body of research behind it (although as usual, not much specifically on cannabis). It’s usually classed in its own category separately from hydroponics, but essentially it is a form of organic hydro.
Aquaponics uses solely organic nutrients and delivers them via a system of recirculating tanks and pumps. The nutrients themselves are supplied from the excrement of fish living in the lower tanks. If using a biofilter, complex molecules and microbial activity are kept away from the root zone; however, some systems do not use a biofilter, instead relying on substrate beds to house the microbe population.
When an aquaponics system is well-established and healthy, it can provide enough high-quality nutrients to successfully grow great-quality cannabis. However, setting up an aquaponics system capable of supporting flowering cannabis may take some time, as fish and bacteria populations take a while to get fully established.
Substrateless Organic Hydroponics (“Bioponics”)
In substrateless organic hydroponic systems, there are no substrate beds to maintain a healthy microbial colony to form. Instead, a specifically-designed biofilter must be used to do the job.
Organic, substrateless hydroponics of this type is often known as “bioponics”. The term was apparently coined by William Texier of General Hydroponics, one of the largest and most influential producers of conventional hydro systems and nutrients.
Bioponics is arguably one of the most “pure” forms of organic hydroponics. It’s an entire school of thought that has been developed with the sole intention of making organic, substrateless hydroponics possible.
The approach, which Texier has developed since first implementing it in 2005, relies on fully-soluble nutrients and a specially-designed biofilter to ensure that complex molecules are processed rapidly and effectively.
The biofilter takes the form of a chamber rich in oxygen and microbial life. It takes in water and complex nutrients, and the microbes – safe in their undisturbed, oxygen-rich sanctuary – can rapidly process the complex molecules within it into simpler forms. After this, the water and processed nutrients are pumped to the plants, where they can be taken up at optimal rates.
What this means is that insoluble nutrients and microbial activity are kept away from the roots, in an entirely separate zone. This provides the advantage of being easier to maintain the root zone in a hygienic condition, while also having tighter control over conditions within the biofilter.
Bioponics can be used with all conventional forms of substrateless hydroponic system – deep water culture (DWC), aeroponics, and nutrient film technique (NFT). It can also be used with systems that typically utilize an inert medium, such as ebb and flow (flood and drain).
Interestingly, bioponics can also be used to culture fish in the lower tanks! The fish can thrive in the nutrient-rich environment and can help process some of those nutrients, as an extra stepping-stone on the way to making them fully available to plants. However, this doesn’t count as a form of aquaponics, as bioponics does not depend solely on fish waste for plant nutrition.
If you’re using a bioponic setup, let us know how it’s working for you in the comments – and if you have any feedback or suggestions about this article, we’re always happy to hear them!
- Disclaimer:Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.