Novice question indeed!!!

[gobytron]

I'm pretty sure I've read in the past that Silica snad can leach lots of nasy stuff...like phosphates.

I'm not 100% on this but I'm sure someone here will chime in who is.

[MitchM]

There are a lot of myths with regards to using silica sand.
Here are a couple of articles/threads discussing/debunking some myths:

http://www.reefs.org/library/article/r_toonen9.html

http://www.advancedaquarist.com/issu...03/feature.htm

http://forum.marinedepot.com/Topic79...ghlight=silica

Mitch