[INXS]

I am wondering how black silica sand would be considered as a substrate.
Having used it for some time now I wonder mainly if anyone knows about any effects it may have on the water or plants nutritionally.

It is 100% silica sand about 3mm grain size, used for sandblasting.
100lb bag is about $10.

I assume it is pretty inert and have added peat+mulm underneath and sometimes mixed flourite with it. The flourite mixed with it made the mix look either "more natural" or "more dirty" - either way I wasn't too happy with it.
The only drawback I find is that it tends to get dirty quick, basically all the fish droppings, dead leaves and other "stuff" that ends up on top of it shows up really easily so you really need to keep it clean for the best look.

When using it I have been dosing nutrients and CO2 regularly and not really noticed any jumps in GH/KH/PH like I see in CC or aragonite sand.

The main advantages IMO are the price and the look of it.

This is unfortunatly the best picture I have that illustrates the substrate.

 

[neonfish3]

I've also been using Black Beauty for about a year now. I love the look of it, and I haven't noticed any changes in Kh/GH/Ph. Mine looks a little finer then yours. Iv'e herd that plant roots can be cut by the sharp edges, but I haven't noticed it my self. Also like you said it does get dirty rather quickly. I have a powerhead blowing lightly across it to help.
I found this info in my research :


Black Beauty® Abrasive

AKA: Boiler slag, coal slag


Chemical Name:

An amorphous mixture of Fe, Al, and Ca silicates

Description:

A black boiler slag abrasive with the following advantages: low
moisture content, high degree of etch for permanent bonding of coatings,
readily used in standard equipment in commerce, inert, fast cutting due
to sharp angular edges, hardness, more economical,longer lasting and
leaves minimum dust

Typical Chemical Composition

Silicon Dioxide= 47.20%,
Aluminum oxide= 21.39%,
Titanium dioxide= 1.01%,
Ferric oxide= 19.23%,
Calcium oxide= 6.80%,
Magnesium Oxide= 1.47%,
Potassium Oxide= 1.60% and
Sodium Oxide= 0.62%

Grades:

Utility Grade #BB1043- A coarse grade used for tough blasting jobs

Medium Grade #BB1243- Used for general purpose repair and maintenance
blasting

Fine Grade #BB2043- Used for new construction, light paint and rust
removal, and for special maintenance applications requiring reduced
profiles

Extra Fine Grade #BB3063- Used to clean surfaces and create a smooth
finish, Brush-Off Blast, or in a high pressure water blast system

Typical Physical Properties:

Particle Shape angular, sharp
Specific Gravity (g/cm3) 2.7

Bulk Density (g/cm3) 75-1-- lbs. per cu. ft.

Melting Point (°C) greater than 2300
Moisture Content less than 0.5%
Conductivity @230°C (cal/s-cm-°C) less than 25 micro Siemens
Mohs Hardness @20°C 6-7
Free Silica less than 1%


Typical Applications:

Used frequently as an sandblast abrasive on sea faring vessels, tanks,
aggregate exposure, castings, structural steel, buildings, railroad
equipment and bridges.

Packaging:

Multiply paper bags, bulk bags and loose bulk

TSCA (SARA Title III) Status:

Unknown. For further information please call the E.P.A.
at 1.800.535.0202

CAS Number:

68476-96-0

Carcinogenicity:
o NTP= No
o IARC Monographs= No
o OSHA Regulated= No

Safety Comment:

When used as a blasting abrasive, carefully review and
follow the recommendations stated in the Material Safety Data Sheet

Trademark:

Black Beauty is a registered trademark of Harsco Corporation, and Black
Beauty ® Abrasive is manufactured by Harsco through its Reed Minerals
Division.

 

[INXS]

WOW, :shock: Thanks for the info - lots of it!

Have you tried to enrich it or in other ways improve the nutritional value of the substrate as available to the roots?

If yes then how?
Thanks