Rock Dust.

[Cannalingus]

Further look into one report found at google:

http://psjc.icm.edu.pl/psjc/cgi-bin/getdoc.cgi?AAAA002030

[I Zimbra]

tis relevent i feel

[Randalizer]

Thanks for the links! I'll have to read later I'm afraid. I think most folks who are successful growers know that moderation and balance are key to optimum health. For instance, upon my research here and elsewhere I've found some numbers as far as how much rock powder to add. I went towards the slightly lower number and will work higher until I can determine an optimum amount.

But a key element here is this. The rock powder I have is for livestock feed. It has to be reasonably safe if it is being sold as livestock feed.

[Cannalingus]

THAT is a good point Randall... I guess it isn't all to bad, but always be sure to use moderation. (Often in organics I find that less is more somehow. (Maybe the elements are so hard to dissolve (unless harsh chemicals and acids are applied) and the minute amounts that are utilized by fungi and bacteria is just about enough to allow for benefits to be had and never will lead to toxicity at all.

I just think that it is safer having any toxins in the digestive system that has developed over 100.000's of years to filter out harmful substances an crap, but when vaporized and inhaled it may become freely flowing in the body and now it can cause real harm in brain and/or lungs at least.

[smeagol]

surely capatonion's post just after bish's on the previous page answers all these questions ... all the facts are there .. his app. rate ties in with the instructions on the bag of rockdust i bought ...

[smeagol]

and u'r 1st link is a study of this

Analysis of Heavy Metal Content in Canabis Leaf and Seed

Cultivated in Southern Part of Nigeria

er excuse me .. think there might be a bit of oil pollution down those parts

[smeagol]

and where did the two venerable scientists in the second link obtain their canna plants from .. come on .. why post links that really are not relevent to growing canna in doors fella ..

[Cannalingus]

The reason for posting those links are for people to read up on the subject and be aware that it does need to be used wisely.

I do not think there is much research done on this topic (regarding indoors potted hemp culture for smoke) so I rather post what I find easily and let the people who don't believe that ingestion of plant matters in toxic soils are questionable, wheter it is organic toxins or not.

But to each his own I guess.

I use rockdust myself as mentioned...-just well within the producers range, and mostly for soil-building and mother plants. (As I don't believe it is really meant to be dosed that way for cannabis or anything to be smoked in vast amounts.)

The produce I smoke is usually made with refined mineral nutrients (and a background of organics to keep lil bacteria happy. (although I discontinue the organics and fish/seaweed stuff around 3weeks before cropping. (I find some products leave metallic tinge in the herbs if used to late in bloom.)

I'm sorry if I have upset anyone or something. I just though it should be menioned.

[Felix Dzerzhinsky]

I think it's a valid point that there's no need to overdo rockdust and I suspect that the plants don't need a huge amount during the few short months they are in the compost. Moderation is always key when adding any ingredients to a compost mix rather than overdoing it. Whether they pick up some of the more unpleasant elements I really have no idea, it would depend on how selective the mycorrhizal fungi are as I should imagine the heavier elements are not water soluble and so would need to be actively absorbed by either roots or hyphae rather than merely diffuse into the roots.

Would seem to suggest some sort of comparison grow with clones to see what differing levels of rockdust have on plants, say starting with no rockdust in the mix up to something fairly over the top. Possibly the results maybe more apparent in a peaty/coir compost that is naturally low in minerals rather than a loam based compost

Anyone up for it ?

[scraglor]

unfortunately the heavier metals are quite reactive and readily soluble in water! which probably explains why cannabis and other fast growing plants are used to remove these contaminants from soil. reed beds are often used as final treatments in sewage works where the outflow water quality regulations are very strict.

from wiki:

Arsenic is very similar chemically to its predecessor, phosphorus. Like phosphorus, it forms colourless, odourless, crystalline oxides As2O3 and As2O5 which are hygroscopic and readily soluble in water to form acidic solutions. Arsenic (V) acid, like phosphorous acid, is a weak acid. Like phosphorus, arsenic forms an unstable, gaseous hydride: arsine (AsH3). The similarity is so great that arsenic will partly substitute for phosphorus in biochemical reactions and is thus poisonous.

i also know lead is farely soluble in ph's much below around 6.2 (i think, don't quote me on it) which is why tap water has to be above this level, to stop leaching of lead into the water supply, from the few remaining lead pipes in the various networks

Edited June 15, 2008 by scraglor

[scraglor]

according to wiki the limits in drinking water are 10 parts per billion, and the analysis shows the rockdust contains - As – Arsenic IMS12Q - 2ppm 5.1ppm - which would seem very high indeed! dunno how this would equate into what the plant would contain, and doesn't actually say how much would be a lethal dose, as i'm guessing you'd have to drink a LOT of water over 10ppb to get sick, but still, when when you get the munchies and all that's around is the rockdust DON"T EAT IT!!! after reading the very low levels needed, and seeing the levels found in rockdust, i dunno if i'll be getting some myself! was a bit concerned when i first saw the analysis, but thought it must be perfectly safe, but think i'll be doing a bit more research before i go smoking weed grown from it!

all from wiki:

Arsenic contamination of groundwater has led to a massive epidemic of arsenic poisoning in Bangladesh[11] and neighbouring countries. It is estimated that approximately 57 million people are drinking groundwater with arsenic concentrations elevated above the World Health Organization's standard of 10 parts per billion. The arsenic in the groundwater is of natural origin, and is released from the sediment into the groundwater due to the anoxic conditions of the subsurface. This groundwater began to be used after western NGOs instigated a massive tube well drinking-water program in the late twentieth century. This program was designed to prevent drinking of bacterially contaminated surface waters, but failed to test for arsenic in the groundwater.(2) Many other countries and districts in South East Asia, such as Vietnam, Cambodia, and Tibet, China, are thought to have geological environments similarly conducive to generation of high-arsenic groundwaters. Arsenicosis was reported in Nakhon Si Thammarat, Thailand in 1987, and the dissolved arsenic in the Chao Phraya River is suspected of containing high levels of naturally occurring arsenic, but has not been a public health problem due to the use of bottled water.[12]

The northern United States, including parts of Michigan, Wisconsin, Minnesota and the Dakotas are known to have significant concentrations of arsenic in ground water. Increased levels of skin cancer has been associated with arsenic exposure in Wisconsin, even at levels below the 10 part per billion drinking water standard.[13]

Epidemiological evidence from Chile shows a dose dependent connection between chronic arsenic exposure and various forms of cancer, particularly when other risk factors, such as cigarette smoking, are present. These effects have been demonstrated to persist below 50 parts per billion. [14]

A study of cancer rates in Taiwan [15] suggested that significant increases in cancer mortality appear only at levels above 150 parts per billion.

Analyzing multiple epidemiological studies on inorganic arsenic exposure suggests a small but measurable risk increase for bladder cancer at 10 parts per billion.[16] According to Peter Ravenscroft, of the Department of Geography at the University of Cambridge [17] roughly 80 million people worldwide consume between 10 and 50 parts per billion arsenic in their drinking water. If they all consumed exactly 10 parts per billion arsenic in their drinking water, the previously cited multiple epidemiological study analysis would predict an additional 2,000 cases of bladder cancer alone. This represents a clear underestimate of the overall impact, since it does not include lung or skin cancer, and explicitly underestimates the exposure. Those exposed to levels of arsenic above the current WHO standard should weigh the costs and benefits of arsenic remmediation.

Arsenic can be removed from drinking water through coprecipitation of iron minerals by oxidation and filtering. When this treatment fails to produce acceptable results, adsorptive arsenic removal media may be utilized. Several adsorptive media systems have been approved for point of service use in a study funded by the United States Environmental Protection Agency (U.S.EPA) and the National Science Foundation (NSF).

Magnetic separations of arsenic at very low magnetic field gradients have been demonstrated in point-of-use water purification with high–surface area and monodisperse magnetite (Fe3O4) nanocrystals. Using the high specific surface area of Fe3O4 nanocrystals the mass of waste associated with arsenic removal from water has been dramatically reduced.

Edited June 15, 2008 by scraglor

[scraglor]

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."

so even if you were growing in pure rockdust you wouldn't be at the level deemed dangerous, so just adding a small amount to your compost it would seem is quite safe! which i kinda guess it would have to be to be sold legally!

just google arsenic and soil, loads of info out there, there are other toxic compounds in there, but i'm guessing they're at perfectly safe levels

Edited June 15, 2008 by scraglor

[Felix Dzerzhinsky]

unfortunately the heavier metals are quite reactive and readily soluble in water! which probably explains why cannabis and other fast growing plants are used to remove these contaminants from soil. reed beds are often used as final treatments in sewage works where the outflow water quality regulations are very strict.

i also know lead is farely soluble in ph's much below around 6.2 (i think, don't quote me on it) which is why tap water has to be above this level, to stop leaching of lead into the water supply, from the few remaining lead pipes in the various networks

Ok that blows that idea out the window

Thanks Scraglor

[I Zimbra]

how about somebody does a 'grow n glow' experiment

[smeagol]

how about somebody does a 'grow n glow' experiment