Lava rock to lighten up soil mix?

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Beachwalker

Well-Known Member
Yes perlite, I usually add about 20% into ffof soil, I'm out of it right now & my hydro store didn't have the size I need last time I went, so thanks for reminding me! LOL
-good luck:leaf:
 
Out Dorothy

Out Dorothy

Member
Sorry, I would like to use lava rock instead of coco or perlite.
To lighten up the soil and provide better drainage.
 
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waterproof808

Well-Known Member
Lava rock is perfectly fine to use as a substitute for perlite. We use it a lot here in Hawaii because it is extremely cheap. You can fill a truck bed for $40.
 
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Beachwalker

Well-Known Member
So if I'm following you want to add it like perlite. I don't see why not, it's generally bigger than perlite although there is some large grade perlite but I've never used it, I'd say go for it

I've used lava rock for sea of green in the distant past so I know of what you speak


..if ripping through the fabric is a possibility then perhaps that's something to consider but as far as loosening the soil that stuff holds a lot of air and water, it's great stuff in Hydroponics, so I'm not seeing how it's going to hurt you in soil ?
 
rkymtnman

rkymtnman

Well-Known Member


my bad, it was Pb in this article. i know i saw another with Hg leaching too but cna't find it.

i'd never use any medium that would leach any heavy metal. more power to ya if you feel differently.

use growstones.com instead.. expanded recyclyed glass.
 
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Beachwalker

Well-Known Member
rkymtnman said:


my bad, it was Pb in this article. i know i saw another with Hg leaching too but cna't find it.

i'd never use any medium that would leach any heavy metal. more power to ya if you feel differently.

use growstones.com instead.. expanded recyclyed glass.
Click to expand...

Thanks for sharing that! I used it back in the 80s & 90s at some point but remember switching to leka, I did not know that and I would like to see that other article if you do come across it, maybe that's why it's not very popular ?

Op can I ask why you don't want to use perlite?
 
stoned-monkey

stoned-monkey

Well-Known Member
rkymtnman said:


my bad, it was Pb in this article. i know i saw another with Hg leaching too but cna't find it.

i'd never use any medium that would leach any heavy metal. more power to ya if you feel differently.

use growstones.com instead.. expanded recyclyed glass.
Click to expand...
do have a link to the study? It is interesting that after 2 years there is no more leaching of lead, but why? was the lava rock fresh from a volcanic field? particular type of lava rock?
too many questions I don't expect you to answer, but a link would help my curiosity. props for looking out for others health.

growstones are awesome, they work as good if not better then perlite and they don't float. I like them even if just for the fact they reduce landfill waste.

so everyone knows perlite is a volcanic rock that has been heated(again after the volcano)
pumice is used in soil mixes, also volcanic
 
too larry

too larry

Well-Known Member
Out Dorothy said:
Anyone use lave rock to lighten soil mixes for fabric pots... like perlite, coco or peat moss?


Thanks!
Click to expand...
I've not thought of it as a weight savings, but I have added it to my soil mix for it's water retention properties. I used about 3-4 gallons in a 45 gallon soil mix. I wash mine to get rid of the dust before adding it to the mix.
 
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waterproof808

Well-Known Member
stoned-monkey said:
do have a link to the study? It is interesting that after 2 years there is no more leaching of lead, but why? was the lava rock fresh from a volcanic field? particular type of lava rock?
too many questions I don't expect you to answer, but a link would help my curiosity. props for looking out for others health.
Click to expand...
Someone from the forum pulled this quote from that study:

"There-fore, we conclude that the soil and/or rocks of the volcanic
area in Hatay are not dangerously contaminated by heavy
metals, and utilization of these materials for agricultural
purposes pose no apparent threat."

There are numerous different types of lava rocks, each with their own unique composition and it also varies by region. In Hawaii, Black/Red Cinder is used extensively in agriculture...it is similar to pumice but a little heavier...it is usually marketed generically as "lava rock." I cannot find any literature that says Cinder contains lead or mercury. If it were hazardous California/Hawaii would not allow its use in agriculture.
 
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waterproof808

Well-Known Member
too larry said:
I've not thought of it as a weight savings, but I have added it to my soil mix for it's water retention properties. I used about 3-4 gallons in a 45 gallon soil mix. I wash mine to get rid of the dust before adding it to the mix.
Click to expand...
Yeah, using lava rock wont save weight at all compared to perlite. Wasnt sure if the OP meant actual weight or just a more airy soil mix? I like about 30% aeration in my mixes.
 
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