WARNING (was dark Sand Substrates)

[Erik Olson <eriko@wrq.com>]

On Sat, 8 Nov 1997, Randy or Deb Carey wrote:

> I have been able to purchase a pitch-black substrate called "Black
> Beauty."  It is a sand blasting material which is inert and comes in
> various fine grades.

Uh oh, that name triggered something I remember archiving, so I looked it
up. (full text in
http://www.cco.caltech.edu/~aquaria/Krib/TankHardware/sand.html).

Randy, have you noticed anything similar to these? ...
   - Erik

"Black beauty sand is actually Metallic Slag from the manufacturing of
copper. It is described as 32-45% SiO2; 25-33% Cao + Mg0; 24-35% Fe0. 

Wondering if the FeO would be a problem, I put about a teaspoon in a very
small jar with some water, shook it up, then tested the Iron content using
a seachem test kit. The results of the first test was 1.0 ppm. I repeated
the test and got 2.0 ppm. This is about 10 to 20 times too much!"

">I used a black sand called something like Marvel black beauty.
>It was very high in Fe and was highly magnetic. It was also very
>sharp. A little piece stuck to a magnetic scraper would scratch
>the glass. It also found its way into small crevices in plants
>and damaged them.
>
>I finally quit using it after an autopsy showed it had shredded
>the inside of a fish. Other than the sharpness and magnetism,
>it was great."