Hydroponics is exploding in popularity among home growers. Though setup costs are typically a bit higher than standard grows, they require fewer resources overall, are relatively easy to maintain, and allow growers to control their growing environment. A balanced nutrient program is essential in hydroponics, because every input your plant receives comes directly from what you supply. This means that you are limited in terms of pH and salinity buffers and need to supply a comprehensive nutrient program for healthy and balanced growth.
Organic matter acts as a buffer in soil-based growing systems. Things like salt content, nutrient retention, and pH are typically balanced by organic matter. Growers can manage this in their hydroponics system by being hyperattentive to the pH, nutrient, and salt content for every input they use. Or, they can add a liquid biological like BIOACTIVETM LiquiLife!
pH
When growing in a hydroponic system, diverse microbes will take on the role of organic matter by regulating plant uptake of nutrients and facilitating pH management. SOM (soil organic matter) offers many negatively charged sites where H+ will bind or release based on existing soil conditions, naturally promoting a neutral pH.
Though microbes can’t change the actual pH of your overall solution, they will facilitate nutrient availability at pH levels when nutrients are not readily available, as well as decrease the energy your plant spends to regulate the pH of the water it consumes.
Check out this blog post for more information on managing pH in your cannabis growing system!
Salt Content
Salinity (salt content) is also buffered by organic matter in the soil, making it a big consideration for hydro grows. Since salt is water-soluble, many inputs that growers will lean on are salt-based. Additionally, salt is naturally present in many water sources, from hard water to city water. There are benefits to some salinity in a hydroponics system, but salt stress is a common issue that may be difficult for plants to recover from. Microbes have a greater tolerance for higher salinity conditions than plants and can prevent plant water loss.
“The NaCl tolerance of microbes far exceeds the salt tolerance of plants. Microbes can concentrate compatible solutes to protect against the osmotic imbalance between the cytoplasm and the environment… microbes have multiple effects on plant ion and osmotic balance, ROS regulation and detoxification, and photosynthesis. These processes are interrelated and ultimately promote plant growth under salt stress via three mechanisms: re-establishing ion and osmotic homeostasis, preventing damage to plant cells, and resuming plant growth under salt stress.” (Liu, et al, 2022)
Reduction in Nutrient Loads
Unlike organic nutrient programs in soil cultivation, hydroponic growing systems need frequent nutrient applications. Daily testing is required in these systems to ensure that pH and nutrient levels are within the desired range, or nutrient deficiencies/toxicities can easily occur. This is especially important to consider when adjusting nutrient levels between stages of growth.
Cannabis can be sensitive to rapid nutrient content changes and is susceptible to toxicities. Microbes can regulate absorption by plants, reducing the impact of nutrient loads and allowing your cannabis to take in the inputs it needs without shocking your system.
Competitive Exclusion & Bio-Sanitation
Diverse beneficial biology plays a crucial role in cannabis grown in any environment; hydroponics is no exception. When growing in a closed system, pathogens can be difficult to treat, and even harder to recover from. Diverse biology creates a synergetic relationship with the host plant, resulting in two protective modes of action related to pests and pathogens: Competitive Exclusion and Bio-Sanitation.
Competitive exclusion on tissue surfaces and root systems naturally engages the plant’s autoimmune defense mechanisms. Competitive exclusion is where two species with equal populations cannot coexist because they fight for the same resource. Both pathogenic and beneficial microbes compete for the “real estate” of the tissue surfaces of the host plant. Beneficial species are living in harmony with the plant, whereas the pathogenic species are competing to rob the plant of nutrients. Put simply, these beneficial microbes on root, stem, and leaf tissues can overwhelm pathogenic species, creating an unwelcoming environment for pathogens to take hold of the crop.
Bio-sanitation is a more active form of pest and pathogen management. Where competitive exclusion creates an environment that isn’t productive for pathogen development, bio-sanitation attacks the problem directly. Certain species of beneficial microbes will consume pathogenic microbes including the microbes that cause white mold and powdery mildew. Rather than being eked out of the environment, pathogens (and some pests) are removed entirely, AND act as a food source for the beneficial microbes that are keeping your plants healthy!
Liquid biologicals like BIOACTIVE LiquiLife™ have shown to be incredibly effective in different growing systems. In hydroponic systems where your plants are not able to lean on organic matter, you may see an increased response to stress factors like salt content, nutrient load changes, and pH. Diverse beneficial biology can mend the gap, and support healthier cannabis, no matter how you grow it.
1. Liu, Yunpeng, et al. “Rhizosphere Microbes Enhance Plant Salt Tolerance: Toward Crop Production in Saline Soil.” Computational and Structural Biotechnology Journal, U.S. National Library of Medicine, 25 Nov. 2022, www.ncbi.nlm.nih.gov/pmc/articles/PMC9712829.
2. McCauley, Ann, et al. “Soil pH and Organic Matter.” MSU Extension | Montana State University, https://apps.msuextension.org/publications/pub.html. Accessed 30 July 2024.
3. Hoidal, Natalie, et al. “Small-Scale Hydroponics.” UMN Extension, https://extension.umn.edu/how/small-scale-hydroponics. Accessed 30 July 2024.