Whee!! I just got me a bag of Perlite today. Which made me smile.
I've just done a thesis on supporting palladium (catalyst in pharmaceutical syntheses) on various microporous solids. ( Pd is expensive and toxic, so desirable to stick it on a solid, so can be recovered by filtration rather that distillation) and went for a variety of microporous solids (synthetic, or very young volcanic ash based solids - ie. only a few millions of years old), and thought.. wow, this is light. Bet it has to be microporous. Checking the packet, it was.
The result of my work was that it does not really matter your solid, pore size, acidity, pore structure, the weather at the time of the experiment, granny's birthday, etc. and that the best support is simply the cheapest one. This would have been great to use in these experiments alongside the fancy expensive synthetic zeolites with perfect 3D pore systems... as at the end of the day, the reaction worked like musical chairs. The palladum popped off the support, did it's business in solution, and at the end of the reaction reattached itself to the solid support. That's the only conclusion that can be drawn.. and it's one that the boss didn't really want to see.
Thankfully I found someone else who had reported the same findings in the literature and had the facilities to measure concentrations of Pd throughout the reaction (which I had not), and so that saved me in the final (oral) exam.
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OK, back to the topic.
Now there's a reason to avoid cat litter!!! In fact our delightful cats have been known to do the biz in a freshly filled plant pot which would have got it's plant after a teabreak.
David L, I hadn't realised there were so many grits. I chose so-called grit sand as I thought the others looked too coarse (I have a 250ml bottle of the coarse stuff) and silver sand looked a lot finer.. too fine.
I might then use JI2 and some of the white stuff, and some gravel. I once got a bonsai as a gift, and the so-called "bonsai soil" which I used in repotting the poor little cramped thing, was full of little white chunks which were probably perlite.
Perlite's home page... plenty of applications for the stuff but no numbers/pie chart on how much is used in the range of applications.
Report on the growth of it's use.. seems horticulture is a small area of the market.
I'd better go easy on the stuff, if Greek islands have to be quarried for it.
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Another thought.. what is the advantage to having air in the compost? Does it prevent anaerobic smelly bacteria getting a hold? Do roots need CO2? Or just to be not constantly in contact with water, so that bacteria can't rot them?
I remember seeing a documentary on Kew where they pumped air into the soil around some huge old trees. I thought that the soil compacting over time had prevented smaller roots from growing. Although this is probably a daft idea - after all, mushrooms can push up paving slabs. Anyone know the reason for doing that to old trees?
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25kg?!? I went on a camping/hostelling tour for a fortnight with 20kg. Let's just say that I NEVER want to pick up 20+ kg ever again.
That was a fortnight of dried food and one change of clothes.. priorities.
Today I invested in a rucksack... so perhaps walking for an hour with all that lot will not kill me next year.
By the way, I am 53kg...
And I'll do my mixing with hands in a bucket, I think..
Until I get my own patch, and a greenhouse..... then I might just need a concrete mixer.