Rock dust... what is too much?

[Reallifegrows]

Hey everyone!

So many of you may know of Mountainorganics on IG, maybe not. I'm intrigued by his more recent soil recipe... previously he had used meals like crab, etc.... now he solely uses rock dust for his micros/macros; I'll post below:

His plants speak for themselves but I would still be concerned with heavy metals such as Iron and Aluminum as such high rates of rock dust.

I know proper lab testing, saturated paste test, tissue analysis, etc is likely needed to find the answer but figured I'd drop this here if anyone has any thoughts or experiences with something like this.

Many thanks :]

 

[Reallifegrows]

Also if anyone knows why my images are posted so small compared to being blown up I'd really appreciate it!

 

[Fitzera]

I've read that basalt rock dust may be preferred to some due to the potential for heavy metals in Glacial and azomite.
I've also read somewhere that you don't need to add them to your soil every season (if we're growing indoor it made me suspect that I could get a few runs in before adding it again)
But i dont know how fast it breaks down to get an idea of when it needs to be replenished.
When I add it, these are the amounts i use for 2 cubic feet of soil:

Azomite 2/3 cup
Glacial Rock Dust 1/2 cup

I also add
Greensand 1 1/3 cup
Rock Phosphate 1/2 + 1/3 cup

I cant really help with the picture part, I upload mine using urls with the little picture button

 

[St. Phatty]

Sort of like working with Gun powder.

Start on the light side and increase the amount of Fertilizer.

 

[Creeperpark]

The key with rock dust is water because without the right water the plant nutrients won't be available. One can use a lot of dust in the soil mix and it will lie dormant unless there's enough Hydrogen in the water to release the nutrients. As you stated above heavy metals such as Iron and Aluminum could become toxic and that is correct too. Toxicity is mostly not determined by the quantity of the dust but the quantity of the water and the pH of the water given. Rock dust fertilizers work best with clean water and not tap water.

 

[St. Phatty]

Turns out that Uranium is also there in smaller quantities.

Pretty similar for Cannabis and the human body.

 

[mexcurandero420]

For heavy metals or uranium you don't have to worry about.If you want rock dust to work, you should mix it with compost or worm casting.Lava rock dust works better than basalt, which has a higher pH.
Another important thing is, is the particle size and that should be >200 mesh like wheat flour.

How much you add, depends on what your soil needs.You can use 1 kg per m2 or max 1kg per 10 l of soil.I also use lava grit 0-3 mm size for the air in the soil.

 

[Creeperpark]

Microbes use the water to convert minerals into salts the plants can use. If I have a ppm over 4000 or EC 4.2 with the runoff from using dust it simply means minerals and not useable salts. So don't flush when using rock dust because its food for later. .

 

[St. Phatty]

For heavy metals or uranium you don't have to worry about.

Definitely wouldn't worry about it. It's too late ! Human bodies have about 90 micrograms of Uranium, and trace quantities of several other Radionuclides.


Does it help with rock dust to use a Bigger Particle size - to slow down the absorption of nutrients by the water ?

Probably depends on the strain.

Maybe it's good to mix up 2 strengths with the rock dust. Then start seedlings in each mix, and see how they do.

One of the reasons I say this - an Apollo 11 phenotype that DOES NOT LIKE hot mixes, but is a WONDERFUL smoke.

She's worth "slowing down" a soil mix for.

On the other hand, some plants LIKE the heavy nutes.

 

[Wuachuma]

Aluminum is not a worry because it is tightly bonded as Aluminum-Silicate - just as with earth's soil.
Iron - I've not had an issue and I go real heavy with various rock dusts

Kelp is a big concern because the ocean is so polluted that a lot of people in the industry are failing soil tests because they are using untested kelp. This is a big issue lately with Build-A-Soil - I've seen several of their customers load out huge legal ops with their soil and fail tests because of the kelp BAS used.
Off the top of my head, I cant remember which kelp products are good or bad, but that can be found on the internet.

 

[flylowgethigh]

Damn, that may be the Fukushima radiation at work.

 

[Wuachuma]

Radiation doesnt show up in a heavy metal test
its due to us dumping industrial waste and sewage into our oceans

 

[crimsonecho]

Aluminum is not a worry because it is tightly bonded as Aluminum-Silicate - just as with earth's soil.
Iron - I've not had an issue and I go real heavy with various rock dusts

Kelp is a big concern because the ocean is so polluted that a lot of people in the industry are failing soil tests because they are using untested kelp. This is a big issue lately with Build-A-Soil - I've seen several of their customers load out huge legal ops with their soil and fail tests because of the kelp BAS used.
Off the top of my head, I cant remember which kelp products are good or bad, but that can be found on the internet.

there are several better options i found during my research for kelp substitutes and thats cyanobacteria. spirulina for example linked to increased yields and better plant health in many studies. its loaded with amino acids and trace elements.

spirulina from a trustworthy brand that has been tested for heavy metals and pollution is a great replacement for kelp imo. it would be even better if you grow it yourself but my space is limited. you can buy the most expensive premium spirulina if you like because really a little goes a long way. its rich in nitrogen so has to be used sparingly anyway.

 

[Wuachuma]

very cool, thank you