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Re: Using Pumice?

> Date: Wed, 10 Feb 1999 19:55:55 -0800
> From: Robert H <robertph at best_com>
> Subject: Using Pumice?
> Since a lot of substrate methods are being discussed here, I thought I
> would throw in another one. I would like opinions on how Pumice could be
> used in a substrate. It is high in potassium and magnesium, but low in
> Fe. 

IDK where that information came from, but it is not true in general.
There are several basic kinds of pumice, but they all are essentially
exploded glass, primarily silicon dioxide. Most other minerals in pumice
gets there by subsequent water deposition, so would depend strongly on
location. Almost all US pumice is mined in the Rockies or the Pacific
coast regions. AFAIK it has little other material than the basic glass.
All other minerals tend to be volatilized and blown away during

> I also understand this is the prime ingridient of the Amano
> substrate. Doesnt this stuff float in water?  How could it be used?
> Mixed with clay?

Like peat, vermiculite and other materials full of air, it must be
boiled to sink quickly, and then kept wet. That is, expand the air to
drive most out and let water get sucked in as it cools.

Its huge resultant surface area provides a lot of chemically active
binding surface, but IDK all the interactions of glass with interesting


Wright Huntley, Fremont CA, USA, 510 494-8679  huntley1 at home dot com
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