Heavy metals in rock dust

[Rurumo]

Hi everyone!
I've been thinking a lot lately about mixing up a batch of Cootz mix for a new grow now that the weather is getting nice and I could get it cooking outside, but after researching heavy metals in mineral salts and traditional organic inputs over the winter, I started wondering about rock dusts. We all know rock phosphate is frequently problematic, and is the primary source of long term cadmium accumulation in agricultural soils worldwide. Likewise, it's becoming a bit more common knowledge that kelp meal (any type of seaweed really) is a significant source of arsenic. These two materials alone are responsible for countless cannabis samples failing their heavy metal testing.
But what about rock dusts? I've used Cootz type mixes off and on for years and have applied rock dusts to great effect in my vegetable garden....but I've never thought to consider their heavy metal content until now. So I went to my trusty site for registered fertilizers-https://apps1.cdfa.ca.gov/fertilizerproducts/-hoping it would be as easy as just typing in "basalt" or "rock dust" and luckily, it was! It won't let me link the exact products to you, but if you search for basalt, rock dust, and azomite, you can find many examples of the most commonly used rock dusts and the results are a bit disturbing. They are variously high in cadmium, arsenic, and lead as well as other heavy metals that you might not really be concerned about, like nickel. Some are high in just a few, others, in all of them. If you use rock dusts, I'd encourage you to go and search the site for yourself. Dolomite also appears to have especially high levels of arsenic, though some samples are no slouches when it comes to other metals.
I've always preferred organic growing, especially outdoors, and I'll continue to do so, but this has really opened up my eyes to questioning the inputs we use. Suffice it to say, I will no longer be using rock dusts of any kind. I hope people wake up to this "hidden" danger of organic growing. Not long ago a ton of organic baby foods turned out to be extremely high in lead-now I'm not all that surprised. Elliot Coleman has been preaching the benefits of rock dusts and remineralizing the soil for decades, and the 2 organic farms I know of make use of it.
What I would like is for organic growers to be as concerned about heavy metals as they are about pesticides or "chemical" fertilizers. Rather than set "low" allowable amounts for these heavy metals, I'd like for regulators to be pressured into setting NO ALLOWABLE AMOUNT-because it's possible, and it's not cost prohibitive to seek out fertilizers and various agricultural inputs that have no detectable level of these metals.
I'm going to take a few days and rework some recipes with materials that are free of heavy metals. Bone meal is frequently tainted, while fish bone meal usually is not, for example. There are excellent replacements for most of these problematic materials. Keep in mind, liquid organic nutrients have many of the same issues-Earth Juice and Nectar For the Gods have many products that contain arsenic and cadmium, while Age Old Organics and Bio Bizz, are mostly clean-Bio Bizz perhaps because as a European product, maybe it's subjected to higher standards?
I'm sorry if I pooped in anyone's cornflakes! BUT, nothing will ever change unless more people know about this and DEMAND change with their wallets! Good luck to you my friends.

 

[MustangStudFarm]

Hi everyone!
I've been thinking a lot lately about mixing up a batch of Cootz mix for a new grow now that the weather is getting nice and I could get it cooking outside, but after researching heavy metals in mineral salts and traditional organic inputs over the winter, I started wondering about rock dusts. We all know rock phosphate is frequently problematic, and is the primary source of long term cadmium accumulation in agricultural soils worldwide. Likewise, it's becoming a bit more common knowledge that kelp meal (any type of seaweed really) is a significant source of arsenic. These two materials alone are responsible for countless cannabis samples failing their heavy metal testing.
But what about rock dusts? I've used Cootz type mixes off and on for years and have applied rock dusts to great effect in my vegetable garden....but I've never thought to consider their heavy metal content until now. So I went to my trusty site for registered fertilizers-https://apps1.cdfa.ca.gov/fertilizerproducts/-hoping it would be as easy as just typing in "basalt" or "rock dust" and luckily, it was! It won't let me link the exact products to you, but if you search for basalt, rock dust, and azomite, you can find many examples of the most commonly used rock dusts and the results are a bit disturbing. They are variously high in cadmium, arsenic, and lead as well as other heavy metals that you might not really be concerned about, like nickel. Some are high in just a few, others, in all of them. If you use rock dusts, I'd encourage you to go and search the site for yourself. Dolomite also appears to have especially high levels of arsenic, though some samples are no slouches when it comes to other metals.
I've always preferred organic growing, especially outdoors, and I'll continue to do so, but this has really opened up my eyes to questioning the inputs we use. Suffice it to say, I will no longer be using rock dusts of any kind. I hope people wake up to this "hidden" danger of organic growing. Not long ago a ton of organic baby foods turned out to be extremely high in lead-now I'm not all that surprised. Elliot Coleman has been preaching the benefits of rock dusts and remineralizing the soil for decades, and the 2 organic farms I know of make use of it.
What I would like is for organic growers to be as concerned about heavy metals as they are about pesticides or "chemical" fertilizers. Rather than set "low" allowable amounts for these heavy metals, I'd like for regulators to be pressured into setting NO ALLOWABLE AMOUNT-because it's possible, and it's not cost prohibitive to seek out fertilizers and various agricultural inputs that have no detectable level of these metals.
I'm going to take a few days and rework some recipes with materials that are free of heavy metals. Bone meal is frequently tainted, while fish bone meal usually is not, for example. There are excellent replacements for most of these problematic materials. Keep in mind, liquid organic nutrients have many of the same issues-Earth Juice and Nectar For the Gods have many products that contain arsenic and cadmium, while Age Old Organics and Bio Bizz, are mostly clean-Bio Bizz perhaps because as a European product, maybe it's subjected to higher standards?
I'm sorry if I pooped in anyone's cornflakes! BUT, nothing will ever change unless more people know about this and DEMAND change with their wallets! Good luck to you my friends.

This is spot on and I can link you to some podcasts that are hours long. Basically, the agronomist that I use suggested that I use sulfates for micronutrients. In the past, I was having my soil tested, reamending my soil, and testing again. What I found with kelp is that my Na levels would go through the roof while Fe and Mn were unaffected. So, I started using way less kelp. These guys confirmed my findings. Also, look into greensand, see if it's contaminated because I still use it.

 

[MustangStudFarm]

There are excellent replacements for most of these problematic materials. Keep in mind, liquid organic nutrients have many of the same issues-Earth Juice and Nectar For the Gods have many products that contain arsenic and cadmium, while Age Old Organics and Bio Bizz, are mostly clean-Bio Bizz perhaps because as a European product, maybe it's subjected to higher standards?

I fixed my soil by using Neem meal, Soy bean Meal, gypsum, Fe sulfate, Mn sulfate, and borax. I was low in N, Ca, Fe, Mn, and B. If you noticed, half of the list was sulfates... Also, skip to around the 58min mark and let it play past 1:00:00 on that video that I linked

 

[green_machine_two9er]

Great thread and excited to see what everyone is thinking. I use bas basalt and Gaia green rock dust.

i have such fear of reducing minerals because I have been preaching and using these rocks dust for years. I still have yet to really understand the whole subject although the idea of organic and inorganic arsenic is something I heard the build a soil guys talking about. Also some companion plants that can reduce hm levels in the soil.
I’ll try to look up that podcast I’m thinking of.

 

[green_machine_two9er]

Ok can’t find the talk but here is something interesting

Heavy Metal Testing Best Practices Living Soil Growers

Heavy Metal Testing and Best Practices for Organic Living Soil Growers We must stick together as a community and handle these problems out in the open for the betterment of all those that are going to grow in living soil and don’t want to be forced into hydro for fear of heavy metals. When we do...

buildasoil.com

 

[MustangStudFarm]

Great thread and excited to see what everyone is thinking. I use bas basalt and Gaia green rock dust.

i have such fear of reducing minerals because I have been preaching and using these rocks dust for years. I still have yet to really understand the whole subject although the idea of organic and inorganic arsenic is something I heard the build a soil guys talking about. Also some companion plants that can reduce hm levels in the soil.
I’ll try to look up that podcast I’m thinking of.

Rock dust and kelp don't have the minerals that we really need though. Every soil test that I have done is coming back low in Mn, like EVERY time. I started using Mn sulfate and less rock dust and kelp...

 

[Rurumo]

This is spot on and I can link you to some podcasts that are hours long. Basically, the agronomist that I use suggested that I use sulfates for micronutrients. In the past, I was having my soil tested, reamending my soil, and testing again. What I found with kelp is that my Na levels would go through the roof while Fe and Mn were unaffected. So, I started using way less kelp. These guys confirmed my findings. Also, look into greensand, see if it's contaminated because I still use it.

I checked greensand on that same site and the numbers varied greatly among the different brands but was typically high in arsenic and lead, with one brand being the highest of any product I've seen recently in lead. Greensand is another thing I used to apply regularly, every three years or so.

Great thread and excited to see what everyone is thinking. I use bas basalt and Gaia green rock dust.

i have such fear of reducing minerals because I have been preaching and using these rocks dust for years. I still have yet to really understand the whole subject although the idea of organic and inorganic arsenic is something I heard the build a soil guys talking about. Also some companion plants that can reduce hm levels in the soil.
I’ll try to look up that podcast I’m thinking of.

Rock dusts are hard to replace-yeah, they're a great source of minerals, but their effect on the CEC was the primary reason a lot of us use them. I was just getting ready to order a bunch of basalt (among others) to amend a big batch of coco-I've been doing tests with single plants and it turns out coco + rock dusts works like a charm! I'm just glad I decided to look them up before I placed the order.

 

[Rurumo]

Rock dust and kelp don't have the minerals that we really need though. Every soil test that I have done is coming back low in Mn, like EVERY time. I started using Mn sulfate and less rock dust and kelp...

I hear you, I usually dose a micronutrient formula once per week for three weeks right at the start of 12/12, no matter what media/nutrients I use. It just seems to really prevent any bottlenecking. I've been using tm-7 by bioag, but that stuff is high in arsenic too, so I've been looking at alternatives. It makes sense, but a lot of micronutrient formulas are high in heavy metals.

 

[Rurumo]

Great thread and excited to see what everyone is thinking. I use bas basalt and Gaia green rock dust.

i have such fear of reducing minerals because I have been preaching and using these rocks dust for years. I still have yet to really understand the whole subject although the idea of organic and inorganic arsenic is something I heard the build a soil guys talking about. Also some companion plants that can reduce hm levels in the soil.
I’ll try to look up that podcast I’m thinking of.

Here is a little something about organic/inorganic arsenic in seaweed.https://www.nature.com/articles/s41598-017-03883-7#:~:text=Introduction,as%20arsenosugars%20found%20in%20seaweeds. It's unclear how much danger this poses. Honestly, it might not be very harmful, but we just don't know. I do know, I wouldn't want my kids testing it out....though I don't have kids...lol. I'm not concerned with the impact this stuff has on my own health, for me it's the principle of the thing. It bothers me that every year our American farmland becomes more and more polluted with these heavy metals, and the consequences for each generation just get that much more serious. It also concerns me that people who are deep into organics (and rightly so!) might not have any awareness of this issue, which probably has a far greater impact on their health than either pesticide residue or GMOs.

 

[Romulanman]

So when does Amazon start their own Moon and Mars nutrient line up? Sending back refined minerals and elements from outer space for weed nutes. It could be a boomin business. Really dope cartoon labels. Prob pay $1k a bottle. Black market would be insane.

Of course that would lead to them using inferior asteroids with lesser grade quality materials. Maybe even resort to using recycled and melted down space junk floating in the garbage ring around Earth. Hell people will still buy it. Its fuckin space nutes man. You kiddin me? Put me down for 2 amigos.

 

[MustangStudFarm]

I hear you, I usually dose a micronutrient formula once per week for three weeks right at the start of 12/12, no matter what media/nutrients I use. It just seems to really prevent any bottlenecking. I've been using tm-7 by bioag, but that stuff is high in arsenic too, so I've been looking at alternatives. It makes sense, but a lot of micronutrient formulas are high in heavy metals.

I don't like using TM-7 because I'll end up with way too much of something that I don't need like Cu or B, like to the point of toxicity. I'm having much better luck using individual sulfates like Fe sulfate and Mn sulfate. If you look at what they use in TM-7, it's just a bunch of sulfates with humic acid... Sucks about greensand because I just bought another 80b bag recently. I've been looking for Mn inputs that are low in P and it's very hard to find. I've been thinking about acid loving plants like blueberries because plants that like lower Ph levels take up more Mn, but Al is also more available, so I'm at a loss. I was looking at making some blueberry KNF and use it on this purple strain that I have. I forget the name, but blueberry and purple strains share the same pigment that makes it purple. I'll google it...

 

[MustangStudFarm]

Anthocyanin is the word...

 

[MustangStudFarm]

So when does Amazon start their own Moon and Mars nutrient line up? Sending back refined minerals and elements from outer space for weed nutes. It could be a boomin business. Really dope cartoon labels. Prob pay $1k a bottle. Black market would be insane.

Of course that would lead to them using inferior asteroids with lesser grade quality materials. Maybe even resort to using recycled and melted down space junk floating in the garbage ring around Earth. Hell people will still buy it. Its fuckin space nutes man. You kiddin me? Put me down for 2 amigos.

This isn't the hydroponic section...

 

[MICHI-CAN]

Out of my league here. But I always sourced my sand or rock dust by origin's geological surveys. Looking for tidal flood plains as opposed to ore and mineral bearing high ground. Sea water is purer and higher in Mg. I no longer get this involved. But a thought that may be worth consideration. Same minerals act very different by locale.

Peace all.

 

[Nutty sKunK]

So when does Amazon start their own Moon and Mars nutrient line up? Sending back refined minerals and elements from outer space for weed nutes. It could be a boomin business. Really dope cartoon labels. Prob pay $1k a bottle. Black market would be insane.

Of course that would lead to them using inferior asteroids with lesser grade quality materials. Maybe even resort to using recycled and melted down space junk floating in the garbage ring around Earth. Hell people will still buy it. Its fuckin space nutes man. You kiddin me? Put me down for 2 amigos.

You get that in rain water... we’ll minute traces of space dust!!

 

[Highlife42]

Yes and yes bro. Keeping going with natural sources lol stone dust is awesome/rock dust. If you need help with how to implement minerals like this I will do my best. Just lmk. Commercial products... lol Screw all them and their nutes. The power of nature my dude, is amazing!

 

[green_machine_two9er]

Yes and yes bro. Keeping going with natural sources lol stone dust is awesome/rock dust. If you need help with how to implement minerals like this I will do my best. Just lmk. Commercial products... lol Screw all them and their nutes. The power of nature my dude, is amazing!

here we go again. More gems from @Highlife42

my dude. I would love for you to explain how to implement minerals like this. In fact that the whole purpose of this thread. How to negate the heavy metals which seem to be in almost every source to some degree.

I fixed my soil by using Neem meal, Soy bean Meal, gypsum, Fe sulfate, Mn sulfate, and borax. I was low in N, Ca, Fe, Mn, and B. If you noticed, half of the list was sulfates... Also, skip to around the 58min mark and let it play past 1:00:00 on that video that I linked

Thanks as always super helpful and great info.

so do you use anyrocks dust in your mix? Just greensand and the sulphates? Just trying to wrap my head around what a recipe would look like without my 2 cups mineral dust off the bat.

 

[Rurumo]

I've started looking up everything that I never thought to in the past on the database-coco coir, sphagnum, ewc, etc. It's really interesting, and it's easy to see how these metals build up to harmful levels in a grow. I'm determined to come up with a mix that has as close to zero heavy metals as possible, but I keep running into problems. The latest "eye opener" is earthworm castings. The best deal for EWC on Amazon is the 30 lb bags of "Red Wiggler" castings-I've bought at least 6 bags of this stuff in the past. Well, these castings have 5 ppm Arsenic, and a whopping 16 ppm LEAD. Most of the castings I looked up were similar, and my thinking is that since we feed the worms a lot of these same rock dusts, they are concentrating the heavy metals in their castings. Even things like perlite and pumice can have heavy metal contamination-the regulations here are meant to protect corporate profits not the consumer, so don't assume that simply because something is for sale, it's not going to hurt you. I've been able to find untainted product replacements for almost all of these inputs however, with the exception of the rock dusts (which are pretty bad), insect frass (another surprise), and a few others. Crustacean shell is usually high in arsenic and cadmium, but many shrimp meals are "not detectable." I know this is a tough pill to swallow for a lot of people who have invested a lot of time, money, and energy into their living soils, but the entire goal is better health for you and the environment, right?

 

[SFnone]

I stick with basalt for rock dust. Everything is going to have some toxic metals, but the only one I personally have hesitations about is Azomite. I can't say I really know for sure, but I've been told by people it has higher doses of heavy metals than others, and that it was originally only meant for decorative bushes and trees... not for anything edible (or smokable)... I'm not at all an expert on it though.

 

[Highlife42]

here we go again. More gems from @Highlife42

my dude. I would love for you to explain how to implement minerals like this. In fact that the whole purpose of this thread. How to negate the heavy metals which seem to be in almost every source to some degree.
..

Are you from Black Fin extracts out of Canada? That is projecting towards NSERC? I ask bc I saw BFE on your page and just wondered what it was. I like where you are going? Medicinal