Silica Sand, Urban Myth?

[Amphiprion]

Originally posted by samtheman
I used silica sand and my grandmother died. Make your own choice.......by by grandma!

Now there's a persuasive argument we should all listen to
I know to never use silica sand now.

[boggerscott]

i dont know were every one is from, but i could get you all the silica sand you would ever want for free. we haul that stuff on the railroad all the time and in our train yard it always spills in between the tracks. it is very white. they mine it from ottowa, il. then it gets brought to chicago and split up to different destinations from there. i know that on the side of the rail cars there is little cards are posted saying that the stuff causes cancer on lab rats. ??? i guess so dont eat it or breathe it i guess. but if anyone needs some let me know.

[ejmeier]

Originally posted by boggerscott
i know that on the side of the rail cars there is little cards are posted saying that the stuff causes cancer on lab rats. ??? i guess so dont eat it or breathe it i guess. but if anyone needs some let me know.

I think the silica dust can (supposedly) cause cancer if you breathe it enough - this might be part of the reason why they don't use silica sand in sandblasting!

[boggerscott]

ya your probly very right. i no the guys at the plant down there get tested alot. so i guess it comes to this " is it really safe for our tanks then?"

[ejmeier]

I didn't mean my previous post to mean that silica was bad for aquariums - just a warning for those that are going to dump 100s of pounds into the tank dry! (That's gotta make some dust.)

I've used silica before, it was alright for the price (practically free!) I don't think you should spend $40 for one bag on the LFS aragonite, IMO. If you can find some southdown, I would much rather use that - I still think it may have some benefical buffering abilities.

But, for the price, I'm looking into this stuff as a good imbetween:
http://www.reefcentral.com/forums/sh...hreadid=676401
Pulverized Lime.

HTH

[luminary]

Originally posted by HippieSmell
Silica has metals IYO? Do you have anything to back that up with, or are you just assuming for some reason?

That's not an opinion, though maybe mis-stated a bit. Typical bagged silica sand from places like Home Depot are not pure silica (you must go to sources like sandblasters for purity...the other advantage to sandblasting silica is that it's actually manufactured beads so the grains won't be jagged/sharp). Silica sands that are not pure will have dirt, plant matter, and all sorts of contaminents, including quite often trace amounts of naturally occuring metals. Also keep in mind that non-pure silica sands may have other artificial contaminents in it just from the packaging process (some working shoveling sand into a processor). I've actually found a penny in a back of Home Depot silica sand before.

Originally posted by ejmeier
I think the silica dust can (supposedly) cause cancer if you breathe it enough - this might be part of the reason why they don't use silica sand in sandblasting!

Actually, silica sand is used quite extensively in sandblasting. When I was looking for it to setup my tank a few years ago, sandblasting companies were the only local source.

Long term exposure to silica dust can cause silicosis. Sandblasters that use it wear masks. It's not a cancer but is still pretty nasty.

[Nabber86]

Originally posted by luminary
That's not an opinion, though maybe mis-stated a bit. Typical bagged silica sand from places like Home Depot are not pure silica (you must go to sources like sandblasters for purity...the other advantage to sandblasting silica is that it's actually manufactured beads so the grains won't be jagged/sharp). Silica sands that are not pure will have dirt, plant matter, and all sorts of contaminents, including quite often trace amounts of naturally occuring metals. Also keep in mind that non-pure silica sands may have other artificial contaminents in it just from the packaging process (some working shoveling sand into a processor). I've actually found a penny in a back of Home Depot silica sand before.

That is true, but there isnt really any reason to beleive that the carbonate-based sands that we typically purchase for our reef tanks (Southdown, for example), are any cleaner than the silica based sands. I seriously doubt that there is much difference in how silica sands and carbonate sands are processed. They pretty much just dredge it up, wash it, and sort it.

As far as sharp edges, sand becomes sand by the process of erosion. By it's very nature of formation most all sand (both carbonate and silica based) tends to be sub-angular and rounded to well-rounded (those are actual scientific terms to describe sand). There really are no sharp edges.

[luminary]

Originally posted by Nabber86
That is true, but there isnt really any reason to beleive that the carbonate-based sands that we typically purchase for our reef tanks (Southdown, for example), are any cleaner than the silica based sands. I seriously doubt that there is much difference in how silica sands and carbonate sands are processed. They pretty much just dredge it up, wash it, and sort it.

True, I thought about adding that comment after I posted but it was late and bed was calling . The sands that are marketed for aquarium usage goes through a much more vigorous cleaning process. As does sands for various other industries (such as sandblasting).

Originally posted by Nabber86
As far as sharp edges, sand becomes sand by the process of erosion. By it's very nature of formation most all sand (both carbonate and silica based) tends to be sub-angular and rounded to well-rounded (those are actual scientific terms to describe sand). There really are no sharp edges.

I think that some general purpose silica "sands" are mechanically crushed. I have bought silica sands before that definitely were not naturally eroded. It just depends on the source I guess...

[Pandora]

Great post. I look forward to getting away from popular untrue myths perpetuated by this anecdotally based hobby. As luminary posted, pure silica dioxide is pretty inert (the purest form is used in gas chromatograms used for scientific analysis of chemical compositions).... the issue is level of purity found in play sands and at the beach.

I too have used it to "fluff up" my sand bed, when I can't find (or afford) enough Southdown or aragonite. Today, my substrate is probably around 30% Quikrete type sand and 70% Southdown type. I haven't noticed any problems... though I do acknowledge issues of the grains being smaller than optimal (packs quite tightly) and edges being sharper... both of which aren't as prefered by dentrivores, but with the mix (aragonite oolite tends to rise to the top), doesn't seem to matter as much. I wonder if the algae myth started because of the concern over more reactive silicates... not silica dioxide, which is basically the same as quartz.

[ejmeier]

Couldn't you just clean the sand to get it more pure? I presonally have never just 'dumped' sand into my tank, I've always rinsed it a whole bunch. (Sifting/straining it might help too.)

Would it be possible to remove some of the (tiny) metal pieces by just going through it with a big magnet?