GlassJoe
Well-Known Member
So, I only recently found this out after doing some investigation, but on the American Association of Plant Food Control Officials' website (http://www.aapfco.org/metals.html), they list the websites where each of the four states mentioned list their analyses for different fertilizers and nutrients sold in the state. You can search by the name of the product, or of the manufacturer, and I attached photos of an example search for a bloom booster I use (GH's Koolbloom). Values are listed in ppm. The search was done on the California Dept. of Food and Agriculture website (https://apps1.cdfa.ca.gov/fertilizerproducts/).
For Koolbloom, I apply on average 2.5 mL-5mL/gallon, and I make 10 gallons to feed 7 plants each week for 10 weeks during flowering. That means the plants get 250-500 mL koolbloom over their lifetimes, split across 7 plants, meaning each plant gets 36-72 mL of the fertilizer during its lifetime. Assuming that it's somewhere close to the density of water, the plants will get 36-72 mg of the fertilizer, which contains 0.26 ppm Arsenic. 36 mg * 0.26 * 10^-6 = 9.36 nanograms, or 0.00936 milligrams of arsenic will be added to the soil over the course of their lives from the fertilizer.
They also won't absorb the entire 9.36 nanograms, some of it will run off or remain in the soil, not all of it will be in the leaf and bud tissue, and anything it does uptake will be divided across the tissue. Therefore I feel good about using Koolbloom on my plants.
One thing that is very important to point out is that this problem is not solved by using organic fertilizers! I've attached a couple search results to demonstrate. The first is one of the first results for "guano" filtered to organic input material. As you can see, it has identifiable heavy metals content, (5.17 ppm arsenic, 0.869 ppm cadmium, 4.04 ppm lead) which may not be enough to cause a problem, but it has to be accounted for in conjunction with other fertilizers to make sure it does not add up to too much.
The second example is Advanced Nutrients popular "Big Bud" nutrient. AN produces and markets both an organic and inorganic version of the fertilizer, but counter to the expectations of many growers, the organic big bud has more than triple the Arsenic and Nickel content of the inorganic version! Neither appears to be a source of other metals of concern, but growers who choose the organic nutrient believing it to be safer may be doing themselves a disservice.
In the actual plant material, metals will often not become concentrated enough to be cause for concern. But if the metals content of multiple fertilizers adds up to too much it can be a health issue. For growers that sell their trim to be turned into distillate, this can be a bigger problem, as the relatively low metals content spread across the plant tissue can be concentrated to unhealthy levels.
For Koolbloom, I apply on average 2.5 mL-5mL/gallon, and I make 10 gallons to feed 7 plants each week for 10 weeks during flowering. That means the plants get 250-500 mL koolbloom over their lifetimes, split across 7 plants, meaning each plant gets 36-72 mL of the fertilizer during its lifetime. Assuming that it's somewhere close to the density of water, the plants will get 36-72 mg of the fertilizer, which contains 0.26 ppm Arsenic. 36 mg * 0.26 * 10^-6 = 9.36 nanograms, or 0.00936 milligrams of arsenic will be added to the soil over the course of their lives from the fertilizer.
They also won't absorb the entire 9.36 nanograms, some of it will run off or remain in the soil, not all of it will be in the leaf and bud tissue, and anything it does uptake will be divided across the tissue. Therefore I feel good about using Koolbloom on my plants.
One thing that is very important to point out is that this problem is not solved by using organic fertilizers! I've attached a couple search results to demonstrate. The first is one of the first results for "guano" filtered to organic input material. As you can see, it has identifiable heavy metals content, (5.17 ppm arsenic, 0.869 ppm cadmium, 4.04 ppm lead) which may not be enough to cause a problem, but it has to be accounted for in conjunction with other fertilizers to make sure it does not add up to too much.
The second example is Advanced Nutrients popular "Big Bud" nutrient. AN produces and markets both an organic and inorganic version of the fertilizer, but counter to the expectations of many growers, the organic big bud has more than triple the Arsenic and Nickel content of the inorganic version! Neither appears to be a source of other metals of concern, but growers who choose the organic nutrient believing it to be safer may be doing themselves a disservice.
In the actual plant material, metals will often not become concentrated enough to be cause for concern. But if the metals content of multiple fertilizers adds up to too much it can be a health issue. For growers that sell their trim to be turned into distillate, this can be a bigger problem, as the relatively low metals content spread across the plant tissue can be concentrated to unhealthy levels.
