Rock Dust.

[Arbuscule]

As far as I understand it the basalt is laced with a myriad of trace elements, some of which would indeed be toxic if consumed in huge quantities, arsenic being one

I think jolene's right in that we consume all sorts of toxins in probably greater quantities anyway, specially if we smoke with fags (I puff like a bleedin chimney)

That said, of course we want to minimise risk. Any concrete evidence of the plants 'passing on' any toxins they've uptaken from the rockdust in the compost would be helpful. I think as Randaliser said we're safe-ish with anything used in agricultural feed. If I'm misquoting sorry

- while we're here can I get all excited about rockdust withnail a rather over-excited thing about rockdust, amazing rockdust almost as old as the planet laden with so many riches

Cheers

A

[scraglor]

well my bag of dust turned up today, so hopefully over the next 10 or so weeks i should be seeing what the fuss is about

[Randalizer]

well my bag of dust turned up today, so hopefully over the next 10 or so weeks i should be seeing what the fuss is about

oh do please keep us posted!

[Davey Jones]

I don't normally do this but this thread is amazing, it just crossed my path again so here

BUMP

This thread should be pinned IMO, theres still people unaware of rockdust!!!

EM2

[908]

Here's something I discovered recently.

When mixing up inoculants that are not going to be sprayed onto a plant and only watered into the soil or poured over the plant with a very fine rose add a small amount of finely sifted rockdust at the same time as adding the molasses and you will observe much faster microbial growth than purely on molasses and seaweed extract alone. The rockdust powder may well damage a sprayer.

A good flour sieve will do the job of sifting but either do it outside or wear a dust mask as this produces a lot of very fine dust particles.

A single heaped teaspoon of finely sifted rockdust will suffice for 10 litres of brewing solution.

e2a: This works better on soil bacteria type inoculants (eg Nitrogen fixers & Phosphorous solubilisers) and is not worth doing with Trichoderma or other species that don't utilise soil borne minerals as they won't use the rockdust.

I totally agree EM2.

Great tip Felix will be tweaking my mix with a bit o rockdust. 908

[Davey Jones]

Its an old favourite of mine, the seaweed extract thread was good too maybe I will bump that next time I cross its path, I learned loads from these threads and my gardens never been greener

EM2

[Randalizer]

If anyone has stopped by my diary lately, you have seen the results of using rock dust. Rock dust does not do any good on it's own. It has to be used with other elements (microherds, seaweed, molasses, etc). But with that said I believe what I have seen is that the rock dust most adds to the girth of stems. With bigger stems come bigger buds.

Edited August 26, 2008 by Randalizer

[scraglor]

all i've noticed from using it (which was what i was hoping actually) is that i can leave my bonsai mums in their pots for much longer without showing the usual micronute deficiencies from being pot bound (with rootgrow in the pots also) they've been in their for a couple of months now, sat outside where they're growing quite quick, i lifted one out of the pot the other day and it's getting pretty rootbound, but no signs of iron/zinc chlorosis that has always shown in the past when i've let em get this tight in their pots

[Jazzy]

I'd have to think about this long and hard before I added this to my mix, heres my 2p

At the end of the day rock dust (basalt) does contain a variety of heavy metals. Plants take up heavy metals from their grow medium and worse, the heavy metals also bio-accumulate:

"The concentrations of heavy metals, including Cd and Zn, in the soils at the investigated sites were above the background levels, and generally exceeded the Government guidelines for metals in soil. The concentrations of metals in plants served to indicate the metal contamination status of the site, and also revealed the abilities of various plant species to take up and accumulate the metals from the soil." (from: http://www.ncbi.nlm.nih.gov/pubmed/12744435 ) There are others on that site, just serach for "heavy metal accumulation"

This link details the possible effects of various heavy metals on the environment/your body: http://www.lenntech.com/heavy-metals.htm (think this is a commercial site, but that particular page doesn't appear to have any commercial orientation and looks to be quite a good quick reference)

So, whilst RD might improve your yield and is organic (as far as possible), when you grind up that bud and smoke it your chances of getting throat/lung cancer could have gone up, possibly by a lot because of those accumulated heavy metals as has been said before, it's risk limitation.

If ganja was legal then there'd be a bunch of scientific papers on this with an answer, until such time I'm not sure I'll use this...

unless someone can tell me that the levels of heavy metals in Rock Dust and compost are comparable and it'd make no difference to the overall levels of heavy metals in my compost mix, then I'd plump for the rock dust and enjoy the bigger buds B)

[scraglor]

if you read through all the posts, you can see, that even if you were growing in pure rockdust, the levels of heavy metals are nowhere near the normal background levels found in soil, so no, there's no way that adding rockdust can bring your compost levels of heavy metal to the recommended safe limits, even if you were growing in pure rockdust, you still would be nowhere near the recommended safe limits.

[Felix Dzerzhinsky]

if you read through all the posts, you can see, that even if you were growing in pure rockdust, the levels of heavy metals are nowhere near the normal background levels found in soil

What he said

[Guest grandad]

rockdust? moonrock, earthrock or blackpool rock. i've been reading about rock phosphate is this the stuff were talking about, rockdust its like saying the pot your growing is called skunk.

[scraglor]

no, rockdust is the dust left over from basalt mining, and contains ALL the known minerals found in soil, you really need to use myco innoculants to make use of it as it not water soluble.

i can say from experience that it works, although in otherwise healthy plants it's hard to see the effects, in my grow diary there's a picture of two mums that i left in the garden about three months ago, they've been left in the same pots and are very rootbound now, whereas in the past (before i cut the roots back and repotted) these very same plants have been left in the same pots in the same compost (minus the rockdust and myco innoculant) after only 1.5 months were showing heavy signs of micronute deficiencies, whereas with the rockdust and innoculants are still healthy after all this time and neglect!!

[Jazzy]

ok after a bit of searching.

seattlepi.nwsource.com/local/vash20.shtml

"In soil samples taken for the latest study, arsenic contamination was found in amounts up to 23 times the state's required residential cleanup level of 20 parts of arsenic per million parts of soil. The biggest hits were found along the eastern edges of Maury Island and in the southern-most sections of Vashon Island.

The study also found up to five times more lead than the level at which cleanup is required, 250 parts per million parts of soil."

Cheeky! The next line is "The natural background levels of these poisonous metallic elements in the Northwest are an average of seven parts per million for arsenic and 24 parts per million for lead." The above quoted levels are the 'cleanup' levels, i.e. it's gotten so bad we have to do something about it now!

I can't find a decent list of the trace elements in soil/compost but from what I've found I'm inclined to agree with you that rock dust isn't likely to contain more than your average compost.

I do wonder though, rock dust has a lot of silicon in it, and if you do a bit of google-age on silicon and plants (I did so just the other day when I came across a bottle of silicon additive on a hydro website) it seems that silicon is a much neglected element that seems to improve plants a lot when added. Could it be that the benefits of rock dust is simply the amount of silicon in it which your indoor pot plants wouldn't normally get enough of?

Edit: spelling fairy

Edited August 31, 2008 by Jazzy

[scraglor]

i think i did somewhere say the average was 7ppm? might not have quoted it directly myself, but that's why i put the link up for people to read for themselves, think the rockdust is something like 5ppm? so once it's diluted in the soil, the amounts you need to mix in will make it MUCH less than 1ppm!

i don't think it's only silicon that makes rockdust good to use, usually i see zinc and iron deficiency first in rootbound plants, not so with rockdust. once these deficiencies have set in it's hard to tell what other minerals are becoming scarce, but it's pretty logical that it's not only these, most composts it seems just don't include enough rock born minerals and rely on the content of the organic matter they're made up from. at the end of the day, a bag aint too expesnsive and will last you years, and it certainly wont do any harm!