Grow stone

Looking at the photo of the bag I can clearly read "100% recycled"
This is pumice. Made in exactly the same way only in a factory and not in a volcano... ...
May I say that I doubt this is pumice. Pumice is not recycled product. It's volcanic rock and there is natural pumice in some islands here in Greece and in Italy.
 
Looking at the photo of the bag I can clearly read "100% recycled"
May I say that I doubt this is pumice. Pumice is not recycled product. It's volcanic rock and there is natural pumice in some islands here in Greece and in Italy.

Read Smoke's post again. I think he is referring to the material makeup and the process. Which is basically silica, melted then cooled fast to cause the material to have all these bubble spaces.
 
Dario, Smoke is describing the method of manufacturing this recycled product (made of melted glasses) therefore this can not be called pumice. It is like pumice. Because it is manufactured by simulating in a factory the conditions of a physical volcanic upheaval. Pumice is a natural product and it is excavated in the quarries.
 
Dario, Smoke is describing the method of manufacturing this recycled product (made of melted glasses) therefore this can not be called pumice. It is like pumice. Because it is manufactured by simulating in a factory the conditions of a physical volcanic upheaval. Pumice is a natural product and it is excavated in the quarries.

I know that and you are right. I also understand what Smoke's message is. So...

I will let you 2 sort it out. ;) Good luck!
 
I have been using it all summer on a bald cypress. 40%composted pine bark. 30% grow stone. 30% expanded shale "haydite". Great results. No usual leaf burn I used to get when the temps get above 100 degrees. Super light. And super porous.
 
I found some at my hydroponics store but the particle size is too large? :(

But re-reading Smoke's article about it, it appears to be fine. I'll probably start using it in my soil mix.
 
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I mixed with expanded shale " haydite" and the particles are about the same size.
 
Because it's not just for looks. Fines can and will clog pots.

I have a couple of little ones that have developed a solid layer at the bottom of their pot. The mix used in those was thrown together quickly - unsifted Turface and some potting soil that was mostly pine bark. A crust has formed on the bottom and the drainage is awful. I'm repotting them this weekend (unless it get colder than expected), and I'll be sifting everything & cutting way back on the organics.

edit: Obviously there are plenty of places on-line where the sift/don't sift debate has been taken up by various folks. I just wanted to add a personal example that helped convince me.

I agree, i've generally sifted all my soils so far. But do you think the biggest problem with the soil you described here was unsifted turface or the fact that you put actual potting soil in your bonsai mix? Probably the potting soil, that's basically adding fines that don't need to be there, as opposed to removing them by sifting.

I suppose the consequences of not sifting vary depending on what components your using and how many fines are in there to begin with.
 
It's basically like fake lava, but the pieces are too big for my liking. I still have a huge bald cypress planted in about a third of this. I can't really judge it because as long as you keep BC wet they will grow in anything.
 
I tried some with a juniper from lowes. Mixed in with clay pebbles and a smidgen of coarse perlite. Worked fine so far (~6 months).
 
Jay I found growstone at the local hardware. Whoo its $40 a bag.... Stay with pumice ;)
 
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