Volcanic Red Lava Rock as S/H media

[rodrigo]

Ok, what's done is done.
Here's a photo of the 2 Cattleyas I just potted in red lava rock.
I'll post another photo in 3-4 months to see the difference.

Rodrigo

[Ray]

As I've said many times - ANY medium can be used for semi-hydroponics, but how well it works for you is going to depend upon your overall cultural parameters. What works well for one may not work well for others.

Unfortunately, flushing alone will not solve lava rock's potential ills. Part of the issue is the accumulation of organic matter and plant wastes, not just minerals. Under the right conditions, that may be a minor issue, but not in most homes.

[rodrigo]

Originally Posted by Ray

As Part of the issue is the accumulation of organic matter and plant wastes, not just minerals.

Wouldn't that be true for any medium? Baked ceramic pellets as well?

Besides, is there a better solvent than pure water for "the accumulation of organic matter and plant wastes"?
If so, I would like to know about it... Maybe I'll stop taking water showers myself

Thanks,

Rodrigo

[Ray]

I think that the reason lava rock accumulates stuff so readily is primarily because the surface is so coarse and jagged. A LECA pellet (good ones, anyway) is relatively smooth, with fine porosity.

I don't think anything that's safe for plants could be better than water as a solvent.

[Aceetobe]

pH ~5 at 2 times with 1 hour in between waterings works better for a flush than pH 7 water.

[rodrigo]

Originally Posted by Aceetobe

pH ~5 at 2 times with 1 hour in between waterings works better for a flush than pH 7 water.

Interesting...
What would be the rationale behind this.
Thanks,

Rodrigo

[got ants]

Originally Posted by Izzie

Thanks for the input/clarification.
Now if only I could find a small enough grade of volcanic rock at lowes and home depot or my garden centers.

What? You don't have a hammer?

[Brotherly Monkey]

Originally Posted by Aceetobe

pH ~5 at 2 times with 1 hour in between waterings works better for a flush than pH 7 water.

Inquiring minds???

[DelawareJim]

Originally Posted by rodrigo

Ok, what's done is done.
Here's a photo of the 2 Cattleyas I just potted in red lava rock.
I'll post another photo in 3-4 months to see the difference.

Rodrigo

I was looking at Rodrigo's picture again last night and noticed his lava rock looks quite a bit different than what we're used to seeing here in the States. His looks more like red gravel.

Compared with what we get;
http://www.greencountrysoil.com/gree...20Red%20Lg.jpg

If that's the case, he should be fine.

Cheers.
Jim

[rodrigo]

Originally Posted by DelawareJim

his lava rock looks quite a bit different than what we're used to seeing here in the States.

Jim:
Well, for clarification purposes, I installed the macro lens on my camera and got a closeup shot of the rock.
This is what came out:



I don't see too much difference from Jim's photo.
It's been very educational for me to look at this close up and see the amazing porosity of this material.

Also, the lousy job I did at washing off all the dust from the rock

The quarry where I get the stuff is on the slopes of the Poas Volcano.

Rodrigo