silica in sand?

[Chris L]

just a question. when i was looking for southdown i found some sand that said it contained small amounts of silica, but it was the same bag that everyone post pictures of. i bought 1 bag and tested it with the vinagar and it did indeed fizzle. i was still leary about using it so i did not. my question is what will the silica do to the tank?

 

[denvig]

Check this out
http://www.inlandreef.com/Testing/SandPhotos.html

 

[Chris L]

so am i to understand that it doesnt actually change tank paremeters but impeeds the growth of good life forms in the sandbed only?

 

[Mini4x]

I was also led to believe that silica sand could have jagged peices, like broken up glass, in it too. I guess the picutres tell the truth, see the nice round particles in the oolitihic sand.

 

[NateHanson]

Some say that silica from sand can contribute to nuisance algae too.

 

[zear0]

Brown diatom algae uses silica for its "skeleton" I beleive.

 

[RichConley]

Brown diatom algae uses silica for its "skeleton" I beleive.

Theres an article by either calfo or shimek or someone like that. It essentially says that the silica in common playsand isnt soluble enough in salt water to make any difference. Like to the point it would take hundreds of years soaking to get to a measurable level. Chances are more silica makes it in through water changes.

 

[Moe_K]

According to the learned chemists in the hobby (I believe I read this in a RHF post first), it'd be just as easy for diatoms to pull silicates out of the silicone which seals glass aquariums as it would be for them to extract silicates from silica sand: in short, no worry.
The Inland Reef test result linked above is worth some thought, though. Will micro-organisms suffer from the sharp edges of the grains?
I have a friend who ran a tank with a silica sand bed for a couple of years, and he had no problem.
Supposedly, one does get a pH or calcium carbonate buffering capacity from aragonite sand (rather than silica sand). I'm not sure if that's true. If it was true, the aragonite sand should be constantly dissolving, right?
Rob Toonen is a big expert on these kinds of questions. He'll be visting the BRS in March. We should pepper him with these types of questions.

 

[Chris L]

thanks moe