I did the exact opposite- White sandblasting sand (quartz). Set up about 6
years ago- never torn down. No 'black line', have lots of cats and loaches
in an 80 gal. Also looks very nice- wouldn't call it natural but is nice
counter point to all the bog log. plants and fish.
SamB

"coelacanth" wrote in message
om...

"Steve Thorp" wrote in message
m...
Hi : I found this material where I work in a hotel, we use it as an
attractive public ashtray filler for people to put their cig. butts out.
It's a real nice semi-shiny black color. I did some research on the
product,
it is called "Black Beauty" Slag Products by Reed Minerals. Its main use
is
for sandblasting and as a grit they use on roofing shingles. here's more
info from the Reed Materials website:
Black Beauty® Abrasive

AKA: Boiler slag, coal slag

Chemical Name: An amorphous mixture of Fe, Al, and Ca silicates

I know the stuff you mean. It would look great in an aquarium.
Unfortunately, it would almost certainly be toxic to plants
and fish. My guess would be it would leech petroleum-like
compounds and metals into the water, both of which are
quite toxic.

-coelacanth