crushed marble

[Jason]

Has anyone used crushed marble as a substrate. The size is about .25 mm
average. Home depot has it here in SoCal for $4.49 a 50 pound bag.

[Stephen]

The problem with using rock of unknown origin and chemical makeup is that it
may leech dangerous metals into the tank..... That is one reason why
specialty marine substrates are so expensive, like the ones from SeaChem
(crushed onyx comes to mind). The rock has had its chemical composition
scrutinized before it is sold as a substrate..


--
Stephen
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"Jason" > wrote in message
...
> Has anyone used crushed marble as a substrate. The size is about .25 mm
> average. Home depot has it here in SoCal for $4.49 a 50 pound bag.
>
>

[SG]

In article >, Jason wrote:
>Has anyone used crushed marble as a substrate. The size is about .25 mm
>average. Home depot has it here in SoCal for $4.49 a 50 pound bag.

My understanding is that the silica in Marble is insoluble. If it is a
fine as you say then it should work in a DSB.

If you ask the right people you should be able to get the rock "Assay"
which will tell you what exactly is in the rock.