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So, are you on the DO train or still ranting about bubblers? If you’re in the latter category, don’t feel bad; at least you’re adding some air to the water your cannabis plant receives.
“It’s better than nothing,” says Dennis Clark, creator and president of Oxygen Research Group, which offers supplemental oxygen equipment. According to Clark, you can have 2 ppm dissolved oxygen out of a well, but with a bubbler you may increase the DO level to 8 ppm, enough for plant growth.
You may be able to do much better, though. Choosing to add dissolved oxygen to your garden is like getting a BMW versus a Kia.
“But what if you got 12 ppm?” Clark asks. “That’s when you start to notice the difference.”
According to Clark, the main difference will be seen in the plant’s root system. Expect whiter, bigger roots with a greater resistance to rot, which is of course the basis of good plant development. Healthy roots result in larger buds and higher yields over time. It also reduces the risk of pythium-induced root rot due to bacterial diseases.
The Problem With Using Bubblers In Your Grow Op
Mentioned before, using bubblers and air stones is a way to increase the DO of your water; however, it does not work as well as having a system that uses electrolysis.
But what if you added more bubblers?
If you aerate your aquarium with an air stone, you might notice that the noise level goes up and your electricity bill increases. Additionally, you’re limited in the amount of DO (dissolved oxygen) that you can draw in this way. Clark says when the bubbles break the surface of the water, some DO is pulled in and captured. However, problem is that bubblers only draw in 21-percent oxygen from the source of air. This means pumping more air through air stones doesn’t actually increase dissolved oxygen levels.
“Bubbles are just the air we breathe,” says Clark. “The air we breathe is 21 percent oxygen and the rest nitrogen.” The other problem with bubblers is they often draw in warm ambient air from a grow room, which could be a grow tent or closet. Oxygen levels should be maintained at 65 degrees Fahrenheit or lower, according to Clark. Anything above that and oxygen levels will diminish. Some growers add chillers, which like adding several bubblers, increases energy consumption.
According to Clark, the most efficient way to utilize nutrients is with a DO of 10-12 ppm. You can achieve this by using electrolysis or adding DO from companies like O₂ Grow and O₂Tube Technologies for hydroponic-, peat- and coir-based grow systems.
according to Clark, the electrolysis cycle produces 100-percent pure oxygen nano bubbles. When reintroduced back into the solution it came from, fifty percent more dissolved oxygen is present. It’s a quiet and efficient way to improve soil quality for plants – whether they’re marijuana or marigolds.
DO is so beneficial that even other big companies, like Dramm Corporation, are taking notice and incorporating it into their own water supplies. They’re now releasing equipment for both small- and large-scale licensed producers to use.
“We realized that we should start paying attention to the dissolved oxygen in our water,” says Kurt Becker, director of commercial products sales and marketing at Dramm. “Growth problems were being faced by some customers with no explanation — they just had issues. It turned out that really low dissolved oxygen was the culprit in many incidences, but nobody thought to check it.”
Becker compares 50 years ago, when growers began to take note of electrical conductivity (EC) in the soil, to today’s situation, stating that “when it comes to recognizing the significance of DO in horticulture, we’re still talking about 50 years ago.”
“We knew that adding fertilizer helped the plant grow. However, increasing EC has resulted in significant increases in plant productivity,” he adds. “The same may be said for pH. If you correct the pH to the proper level, nutrients will be better absorbed and your plants will be healthier.” He believes that if you measure your water’s DO and make needed adjustments, similar benefits will result.
“Now, we know that dissolved oxygen is the third measurement that people haven’t been paying attention to,” Becker adds.
Measuring Dissolved Oxygen In Cannabis
growers who don’t measure the level of dissolved oxygen (DO) in their water are missing out on potential benefits for plant growth. Although technology to measure DO isn’t entirely new, it seems that many growers aren’t taking advantage of it.
Although many growers grasp the importance of achieving the right pH, EC, and dissolved oxygen levels, few have the proper tools to test for DO levels.
“There’s hardly ever two growers that do things the same way,” he said, “so you gotta learn about your own water. It might be one thing in Detroit and may not work for somebody in Nebraska.”
Many growers are unwilling to measure DO because the gadgets can be expensive, compared to other pH or EC meters that cost around $30. Another reason is that, like any new technology, it requires a lot of learning and practice before becoming familiar with it. For example, Hanna Instruments offers video training on using DO meters starting at only $295. However, as with anything you purchase—you get what you pay for; The more features you want/need usually means paying more money for the product.
A Hanna Instruments company spokesperson admittance, “People can be overwhelmed by the technology,” is what they’re trying to fix with their new video series– making the concept less daunting for consumers.
think about what they say in those intolerable Capital One credit card commercials: “What’s in your wallet?” Growers need to ask themselves, instead, “What is polluting my water?”
According to Hanna Instruments, its Optical Dissolved Oxygen Meter doesn’t require a minimum flow rate like other meters on the market. This makes it more accurate and reliable for users. It typically retails for $1,450.
Noticing A Difference In Cannabis Plant Growth
Sonja Maki, Ph.D., is an assistant professor at the College of Agriculture, Food and Environmental Sciences located in University of Wisconsin-River Falls. In a study conducted with graduate students at The University of Tennessee, improved root development and growth was observed in plants. According to Maki,”We had been noticing poor root development in two hydroponic settings prior to the study”.
“We were seeking to enhance plant growth in a vertical green wall and an NFT [nutrient film technique] system when we noticed that the DO was quite low at 5mg/L. We attempted adding air stones, but it didn’t improve matters much.”
Maki tells me that she conducted an experiment on crown peas grown in a greenhouse with NFT technology with an undergraduate student. “We picked the crown pea, a determinate plant, because they also grow wide at the top and produce a lot of flowers,” she continues. They conducted tests comparing the control group to O₂ Grow’s technology, and there was a significant difference in growth between the experimental plants.
The difference between the experimental group and control group was significant; the former had taller plants with better root growth that branch more. This is due to oxygen levels, as those in the experiment had access to more oxygen. Theroots of the plants in comparison were brownish with lateral roots terminating prematurely while those inthe experimental group had longer healthier roots. In the end, Maki claims that she and her team were able to create about 8 mg/l of DO in the water the plants were growing in using a three-in-one meter that also measures pH and EC. She concurred that there are alternative methods for increasing DO levels in the water. However, this method helped growers increase root development and plant growth at a low cost.
Ozone In H2O For A High-Yielding Cannabis Crop
Ozone (O3) is a powerful oxidizer that, when used in irrigation systems, will clean the pipes by breaking down organic material and biofilm in the water. So, how does this relate to dissolved oxygen? With cleaner pipes, there is less demand on oxygen which helps maintain higher levels of DO. The increased solubility of O3 in water is responsible for the higher amount of oxygen that it dissolves in water, which is important for cannabis growers. According to Becker, by incorporating O3 , irrigation systems may be better maintained. Although these technologies are pricey, they may be worthwhile investments for big-scale farmers and licensed producers who want to stay competitive.
In conclusion, adding dissolved oxygen and ozone to your grow op could be the key to better root development, shorter cropping time and bigger buds. Meters are relatively inexpensive, but the technology to deliver these gases, particularly ozone, can be expensive. Cannabis cultivators need to look at the cost of the various units and determine which ones will deliver the best return on investment for their operation.
