West1;1614141; said:Looking for some substrate that is Non-Silica and that will not get caught in the filter (I hear fine sand is a pain)
i believe all sand and gravels have silica in them.....
why are you specifying non silica ??
silica is the chemical compound silicon dioxide, also known as silica or silox (from the Latin "silex"), is the oxide of silicon, chemical formula SiO2, and has been known for its hardness since the 9th century[1]. Silica is most commonly found in nature as sand or quartz, as well as in the cell walls of diatoms. It is a principal component of most types of glass and substances such as concrete.

