BCSS - Forum

HaoBao wrote: ↑Fri Jan 22, 2021 9:18 pm Had a look for vermiculite and it said some might contain asbestos. Anyone know anything about that?

Yup you have been warned about adding synthetics to compost ... that goes for all synthetics.
Ventilation! Care!

What is a synthetic?

Are akadama and pumice OK because they are used as dug from the ground?

Are moler, perlite and vermiculite not OK because they have been heat-treated?

Terry S. wrote: ↑Sat Jan 23, 2021 9:26 am What is a synthetic?

Are akadama and pumice OK because they are used as dug from the ground?

Are moler, perlite and vermiculite not OK because they have been heat-treated?

My understanding that some of the materials mentioned are processed as opposed to merely extracted (like grit). Some of these involve heating and other processes including chemical ones. Since many of these materials include silicates, they present a risk to health ... ingestion ... breathing. My understanding is that all silicates which are in small particle size or could become small particles by even light crushing, should be treated with care and respect. That would make pumice perlite vermiculite and fired clay not OK.
I would treat any powder material with respect .... ventilation and masking and gloves should you be using it often and in large quantities.

el48tel wrote: ↑Sat Jan 23, 2021 12:58 pm I would treat any powder material with respect .... ventilation and masking and gloves should you be using it often and in large quantities.

Studies seem to show that perlite is one of the safer silica/silicate materials to handle. Obviously still use a mask and clean up the dry stuff as soon as you can. I knock the dust out of the air with a water spray if it gets visible.
https://www.tandfonline.com/doi/pdf/10. ... 014.881940

Re:- VERMICULITE AND ASBESTOS
It is not about processing but extraction of the raw material. One mine in the US, at Libby, had an asbestos deposit at the mine. As a result much of their output, from the 1920s to the 1990s (ish) was contaminated in some way. It was much used as insulation in the US over those decades and a very substantial proportion of the US vermiculite was contaminated.
While there will remain contaminated insulation, I assume new vermiculite is OK now.
You can chose your materials based on a variety of reasons. I agree that materials with a high carbon footprints are unattractive if a lower footprint alternative will do the job. But I wouldn't discount processed materials just because they are processed. My house would be drafty without the bricks, for a start.
Any dust from whatever cause out to be considered potentially dangerous to your lungs. Some are worse than others of course, but if your material is dusty: damp it down, wear a mask or avoid using it.
Cheers
David

Third one through today. I'm alternating sphagnum / vermiculite mix with them to build up the numbers in each to see how they do. So this one is in the sphagnum and you can see number 1 next to it to see how well it is doing.
'Number 1', on the right hand side is now 7 days out of water.

When did you sow yours ?, no show for mine getting a bit impatient

Tina wrote: ↑Sun Jan 24, 2021 10:20 am When did you sow yours ?, no show for mine getting a bit impatient

Mine went into water on 29th December. Been on the top of a dresser in the kitchen (around 18 degrees in there) since. Mine didn't do anything until I told them that Darren on here had two germinated! Maybe they need a good talking to Tina?

(Don't read this Tina!)

4 and 5 through today but I wanted to post as I think I'm starting to see early differences in development.

The second seed to go in the sphagnum is developing in a different way to the first seed in the vermiculite. Both are growing but the ones in the sphagnum have produced a load of fine root hairs and seem to develop the first leaf much more quickly.
Now, of course, my sample size is currently shocking and also this is still very early days (9 days for the oldest) and the ones in sphagnum could go downhill or stall later but I'm pleasantly surprised so far!

I am following the thread closely as am going to try a similar top layer of sphagnum moss for my Haworthia seeds. Just a comment on the fluffy roots, I am not sure this is what you really want, as later on, when they reach the base substrate, or you will want to start a wet-dry cycle, "regular" roots would need to develop anyway. This is at least what I observed on some cuttings rooted in water and then repotted to the normal substrate.