Can you use red lava yard-rocks for grow medium ?

[grow4fun]

Iâ??ve heard people mention â??lava rocksâ?? as a grow medium, instead of Hydroton. Are they talking about special lava-rocks sold at a grow store, or the red lava-type rocks used for landscaping, that people use in their front yard in place of grass ?
The yard kind is probably very cheap compared to Hydroton (they probably sell it by the cubic yard like soil). What I wonder is:
1) does it release minerals into the solution that would raise/lower the pH ? and
2) does the rock being red mean itâ??s got a lot of iron in it, which is toxic to plants (except in micro dosages) ?
Has anybody grown in red yard rocks?

grow4fun Reviewed by grow4fun on 02-03-2006. Can you use red lava yard-rocks for grow medium ? Iâ??ve heard people mention â??lava rocksâ?? as a grow medium, instead of Hydroton. Are they talking about special lava-rocks sold at a grow store, or the red lava-type rocks used for landscaping, that people use in their front yard in place of grass ? The yard kind is probably very cheap compared to Hydroton (they probably sell it by the cubic yard like soil). What I wonder is: 1) does it release minerals into the solution that would raise/lower the pH ? and 2) does the rock being red Rating: 5

[MaryjaneMenehune]

I do not know exactly what hydroton is, but i think you might be referring to rockwool or a brand name associated with rockwool... rockwool is available by cubes as well and can be purchased on ebay occasionaly. Most of the stuff specially formulated for high performance is just a tried and true thing tweaked slightly, you may find out, upon a little more research into some forums, about the differences if any... i hope this can be of some use.
-mjmenehune

[NugsNjugs]

Whats crackin all?

OK, if your gonna use red lava rock from your yard please put it through a serious bath first, soak it in PH'd water (5.5), then run it through your stove for 30 minutes to kill the crap from your yard.

Hydroton is basically expanded clay pellets that in no way compare to rockwool. Hydroton I believe is a brand name.
Peace.

[BloodShot420]

I use hydroton in my DWC... i must say - it works awesome, but its a bitch to clean.

it will not change the ph of your water... and they are small, and pretty light... they wont crush your plants, or cut them - even seedlings...

hydroton gets my vote.

[turtle420]

Whats crackin all?

OK, if your gonna use red lava rock from your yard please put it through a serious bath first, soak it in PH'd water (5.5), then run it through your stove for 30 minutes to kill the crap from your yard.

Hydroton is basically expanded clay pellets that in no way compare to rockwool. Hydroton I believe is a brand name.
Peace.

Sounds like good advice to me!

As to the lava rocks, the ones I'm using are your typical Home Depot BBQ lava rocks... just crush them a little bit so they aren't that big, and just use them. Definitely you HAVE to wash them before use. But they're good for that purpose.

There are some people that preffer lava rocks to Hydroton Pebbles, as the pebbles might shift and cause excessive stress to the girls' roots. In any case, to each his own. NugsNjugs' advice is good!

Best,

-turtle420
.

[BloodShot420]

I only fill a 6" netpot with hydroton... i'm not sure how they would hold up to a big E&F tray... I was thinking about trying it this summer.

[grow4fun]

Wow, barbecue rocks. Never seen those before. Thanks. They look better to me than clay pebbles. I am still interested in the use of landscaping rocks (I would clean/sterilize them of course). Larger volumes of them would be way cheaper [than barbecue or hydroton].
People tell me their experiences with [something], but when I do my own experiments I come out with completely different results. For instance Hydroton. â??It doesnâ??t affect the pH of waterâ?�. In my experience that statement would be true only if youâ??re using tapwater, where the pH is already high 7.2 â?? 8.2. I washed my hydroton a dozen times. Then immersed it in a volume of pure R.O. water (pH 6.2), waited overnight, and it invariably raised the reading to around 8 â?? quite unacceptable. Tried it several times. Good pH meter, tested, calibrated; a solid experiment. And no matter how many times you wash them, more red powder keeps coming off â?? you could wash them until they disintegrate!. Guess I could do what other people do: use pH down and get over it.
Maybe there are different brands of pebbles. Iâ??ve read that some â??cheap agriculturalâ?? brands do leach and raise the water pH. I got mine from a growstore, but maybe that brand has started using the cheap stuff. Or maybe itâ??s all that wayâ?¦â?¦â?¦

[Da1KrayzieThug]

I believe lava rocks might have nutrients and other materials stick into their structures and might get released later. I'm not sure about this but if lava rocks really do some from volcanoes then I'm sure they would have something in them that might make pH or ppm level fluctuate later on. I would just stick with the hydroton and stay away from the rockwool since Zandor hates it so bad for the same reason I think lava rocks might be bad. Goodluck <3

[latewood]

Iâ??ve heard people mention â??lava rocksâ?? as a grow medium, instead of Hydroton. Are they talking about special lava-rocks sold at a grow store, or the red lava-type rocks used for landscaping, that people use in their front yard in place of grass ?
The yard kind is probably very cheap compared to Hydroton (they probably sell it by the cubic yard like soil). What I wonder is:
1) does it release minerals into the solution that would raise/lower the pH ? and
2) does the rock being red mean itâ??s got a lot of iron in it, which is toxic to plants (except in micro dosages) ?
Has anybody grown in red yard rocks?

hey carolina boy...look here, lave rock is usually added to the bottom of the pot in so9il plants to increase drainage...If you tried to use it in dwc/hydro it would work, I think but, you would not hold moisture as much, It won't hurt anything, and I think it's red, because they call it 'lava rock'...hydroton is the shit...It is reusable and provides anexcllent medium for hydro...Imho.lw

[latewood]

Whats crackin all?

OK, if your gonna use red lava rock from your yard please put it through a serious bath first, soak it in PH'd water (5.5), then run it through your stove for 30 minutes to kill the crap from your yard.

Hydroton is basically expanded clay pellets that in no way compare to rockwool. Hydroton I believe is a brand name.
Peace.

This is the thing to do with yard rocks and soil, if you choose to dig up your own medium...
This is good advice.lw