silica in the system

[pdhenderson]

Debate silica use and prescence

[Travis L. Stevens]

Uh.... have anything to go off of first?

[pdhenderson]

Well Im standing with my original statement that silica should be avoided in our systems, not only in our systems, but in our lives in general.
Having worked for an enviromental protection supply company I have witnessed and experienced the effect of prolonged exporsure to silica based products, that being nose and throat irritation aswell as a burning lung sensation.

I have replaced all my play sand in my sons sand box with silica free sand, although it is hard to avoid silica 100% as it is used in the filtering of tap water in some municipalities we can always unkowingly import it.

I believe that silica posses a threat to the general health of our systems that we are trying to keep. Because a bloom dies doesnt mean that they are all gone. Originisms such as these like common bacterias can rest in dormant stages untill available food sources or need nutrients are present.

Some or alot of people have used silica and have not had any consequences, ythese are the few not the norm.
AS such when you see Diatom filters you will see that the are not recommended for prelonged exposure.
And as stated by Mr Wilson, whent he blooms return, people associate it with water params, photo, and photoperiods, and often over look the source water and the susbstrates that have been added into their systems.

I have just completed my live rock, with I have a diatom bloom, sure, did I source out silica free products, yes, are they? probably not. But I believe that using a silica based product is asking for trouble. Sure the member who stated that he/she was using it and was not using a 100 lbs of it, might have a bloom that could abate quickly but I believe that this is a source for future problems.

[HBtank]

I think it is always present and an essential part of most aquariums.

In fact if I were to remove it all my livestock would die within an hour..

It holds all my water and fish inside...

[Travis L. Stevens]

Originally posted by pdhenderson
I believe that silica posses a threat to the general health of our systems that we are trying to keep.

I believe this to be relatively true and believe as well, but not with the same zealous invigoration that you do.

Because a bloom dies doesnt mean that they are all gone. Originisms such as these like common bacterias can rest in dormant stages untill available food sources or need nutrients are present.

What are you talking about? You'll need to explain yourself a little better here to be fully understood.

Some or alot of people have used silica and have not had any consequences, ythese are the few not the norm.

Correct. No one is disputing that.

AS such when you see Diatom filters you will see that the are not recommended for prelonged exposure.

Correct....

And as stated by Mr Wilson, whent he blooms return, people associate it with water params, photo, and photoperiods, and often over look the source water and the susbstrates that have been added into their systems.

What are you talking about? Mr. Wilson hasn't said anything like that in here. You and I are the only ones that have posted.

I have just completed my live rock, with I have a diatom bloom, sure, did I source out silica free products, yes, are they? probably not. But I believe that using a silica based product is asking for trouble. Sure the member who stated that he/she was using it and was not using a 100 lbs of it, might have a bloom that could abate quickly but I believe that this is a source for future problems.

Once again you are unclear what you are talking about and where this is stemming from. Care to clarify?

[HBtank]

Originally posted by pdhenderson
Well Im standing with my original statement that silica should be avoided in our systems, not only in our systems, but in our lives in general.
Having worked for an enviromental protection supply company I have witnessed and experienced the effect of prolonged exporsure to silica based products, that being nose and throat irritation aswell as a burning lung sensation.

I have replaced all my play sand in my sons sand box with silica free sand, although it is hard to avoid silica 100% as it is used in the filtering of tap water in some municipalities we can always unkowingly import it.

I believe that silica posses a threat to the general health of our systems that we are trying to keep. Because a bloom dies doesnt mean that they are all gone. Originisms such as these like common bacterias can rest in dormant stages untill available food sources or need nutrients are present.

Some or alot of people have used silica and have not had any consequences, ythese are the few not the norm.
AS such when you see Diatom filters you will see that the are not recommended for prelonged exposure.
And as stated by Mr Wilson, whent he blooms return, people associate it with water params, photo, and photoperiods, and often over look the source water and the susbstrates that have been added into their systems.

I have just completed my live rock, with I have a diatom bloom, sure, did I source out silica free products, yes, are they? probably not. But I believe that using a silica based product is asking for trouble. Sure the member who stated that he/she was using it and was not using a 100 lbs of it, might have a bloom that could abate quickly but I believe that this is a source for future problems.

I agree on the respiratory implications of silica, but this really is irrelevant and the rest of your post is really based on pure myth based on assocition with a name. Silica sand by nature does not have water soluable silica. It really is unfortunate that so many people just take the name of the "silica sand" and make assumptions. Silica that is water soluable can be found in any sand with imputiries, and therefore the cleanliness of the sand is most important. Aragonite, silica sand, any sand, can be "dirty" and have these kind of impurities.

Again, as stated many times, if you think that "silica sand" is dissolving into your tank, you better start worrying about the glass on your tank too...

Anyways, I have run a full silica sand DSB tank (over a year now) without a diatom bloom since the first two months.

[Travis L. Stevens]

HBTank/pdhenderson: You both have valid points, but they both come from unstable information. I highly recommend reading through this article: http://advancedaquarist.com/issues/jan2003/feature.htm

[HBtank]

I have read it and weighed it into my argument. Far to little data for me to treat it as gospel and it backs my statements as much as it does any others.

[Insane Reefer]

Let's see some pictures of Established Tanks that use ONLY Silica for the sand bed.
Since some folks are saying they have never, ever seen a successful tank that uses a silica sand bed...

[HBtank]

Since I am already here, here is a shot from about a year in, or about 4 months ago.




Notice the diatom encrusted sand

[badfish03]

HBTank how deep is your sand bed in that tank?

Robert

[rustybucket145]

Man am I confused.....? Who is Mr. Wilson...?

pdhenderson-->> put down the silica pipe and 'splain yourself!

Also, are you aware that most (not sure of exact number here) beaches in the world are composed of silica based sand.....?

[Travis L. Stevens]

Silica sand by nature does not have water soluable silica.

If you read the article, you will find that silica sand does release silicates, but it does not say if it is from the quartz crystals in the sand or if it is already in the sand. Either way, the point is moot because silica sand doesn't release much more free silicates than what occurs naturally as freshwater from rivers enters the ocean.

It really is unfortunate that so many people just take the name of the "silica sand" and make assumptions. Silica that is water soluable can be found in any sand with imputiries, and therefore the cleanliness of the sand is most important. Aragonite, silica sand, any sand, can be "dirty" and have these kind of impurities.

Completely agreed. Now, to say that silica sand doesn't release silicates is bogus, just like you stated. But it doesn't necessarily come from the quartz crystal (silicon dioxide)

Again, as stated many times, if you think that "silica sand" is dissolving into your tank, you better start worrying about the glass on your tank too...

Actually, that's not completely true either. Glass isn't made of 100% silicon dioxide but a large amount of other materials, too. If it was 100% quartz, then there would be no such thing as starphire (low iron) glass.

[HBtank]

Originally posted by badfish03
HBTank how deep is your sand bed in that tank?

Robert

It is about 4 inches on the sides/back. About 2 inches in the middle/front.

I also have a 5" silica DSB in my sump that is about 15" X 12".

[reefshadow]

I've used silica sand for years and never had a problem I could attribute to its use.

6ish months after setup, couple of years ago-



6 months ago-



No today pics, but it looks just as clean. Sand is white, and I can't say I've had a "problem" with diatom growth. I get no more than I ever got with aragonite, or even BB. Have used quickrete medium grade silica sand in at lest 6 tanks in the last 5 years.

Now I know i'm not TOTM material, but I think my tank is pretty nice. Coral health is good and when it hasn't been the reasons have been definately attributable to everything BUT the sand, usually me making errors in judgement.

BTW, the sand is used raw out of the bag, not rinsed at all. I'll stand by it because it has always worked for me.

I'm not worried about it.

[HBtank]

Originally posted by Travis L. Stevens
If you read the article, you will find that silica sand does release silicates, but it does not say if it is from the quartz crystals in the sand or if it is already in the sand. Either way, the point is moot because silica sand doesn't release much more free silicates than what occurs naturally as freshwater from rivers enters the ocean.


Completely agreed. Now, to say that silica sand doesn't release silicates is bogus, just like you stated. But it doesn't necessarily come from the quartz crystal (silicon dioxide)


Actually, that's not completely true either. Glass isn't made of 100% silicon dioxide but a large amount of other materials, too. If it was 100% quartz, then there would be no such thing as starphire (low iron) glass.

I definately do not disagree. And that article is a great one and I do understand his finer points. What I took away in the end is that the production and quality of the material was more important than the material itself in terms of silica.

But this myth is one big generalization to start with. Gotta fight fire with fire.

[Insane Reefer]

Travis (and others that are confused by vague references to other conversations), the DIY thread has turned into a debate about the use of silica sand, and most of the quotes and statements that seem to make no sense, do, if you read the last page or two over there...

Ok, I'm going out on a limb here...

I'd like to know where the idea of silica sand not being inert came from. Randy Holmes? One guy, who did one test on one aquarium? No disrespect intended, but seriously. If a real scientist tried something like that with his peers, he'd be laughed out of the field...
It can be called an experiment, but unless dozens of identical tanks are tested, and the results can be verified, it is simply theory.

When I google "silica sand" +inert, I get 58,000 returned hits.
The only place I can actually find anything about silica not being inert, is on reef boards and aquarium boards. Or if it is placed in Hydrofluoric Acid, or if it is heated above 800°F.
Please, if someone has an article not written by a reef geek, that says otherwise, please post it.

http://www.setonresourcecenter.com/m...5/wcd04511.htm
http://en.wikipedia.org/wiki/Silica
http://www.mineralsuk.com/britmin/mpfsilica_sand.pdf
http://www.samsa.org.uk/silica.htm
http://www.uncp.edu/home/mcclurem/ptable/silicon/si.htm

Sure the member who stated that he/she was using it and was not using a 100 lbs of it, might have a bloom that could abate quickly but I believe that this is a source for future problems.

This is a snippet taken from Wiki, on Diatoms:
In the open ocean, the condition that typically causes diatom (spring) blooms to end is a lack of silicon. Unlike other nutrients, this is only a major requirement of diatoms so it is not regenerated in the plankton ecosystem as efficiently as, for instance, nitrogen or phosphorus nutrients. This can be seen in maps of surface nutrient concentrations - as nutrients decline along gradients, silicon is usually the first to be exhausted (followed normally by nitrogen then phosphorus).

When I said that available silicates would be quickly consumed, I meant just that. Unless silica/silcon has the ability to reproduce, then once its resources are consumed, there is nothing else to worry about - more silica isn't just going to spontaneously sprout from the rock.

[Travis L. Stevens]

Nice tank, ReefShadow. I was wondering what it looked like.

I definately do not disagree. And that article is a great one and I do understand his finer points. What I took away in the end is that the production and quality of the material was more important than the material itself in terms of silica.

I agree wholeheartedly. The quality of the material used makes a huge difference. But even 100% silica sand (AKA Sand Blasting Sand) tanks are wonderful. There is someone around here with it, I just can't remember their screen name.

Travis, the DIY thread has turned into a debate about the use of silica sand, and most of the quotes and statements that seem to make no sense, do if you read the last page or two over there...

Ah, I see. I haven't touched that thread because I just can't get caught up with it. It moves too fast. I'll be online at home on Thursday, so expect a huge update by me soon enough

When I said that available silicates would be quickly consumed, I meant just that. Unless silica/silcon has the ability to reproduce, then once its resources are consumed, there is nothing else to worry about - more silica isn't just going to spontaneously sprout from the rock.

DING DING DING! We have a winner. That says it all right there. Now, one thing to understand is it might take time for the free silicates to come out of rock/sand thus prolonging the release of silica. It's not like all the silica is available at once to be used and then it is suddenly gone, but rather the excess silica is taken up in a bloom and the silica users (sponges, diatoms, etc) will die away as the population matches the rate of release of the silica. It could very well be unnoticable with how slow it could release, or noticable if it is released fast enough. One final point is water quality. Those without DI units could very well be leaving available silicates in the water as the DI unit is what takes it out. For those unlucky individuals with large amounts of silicates in their water and have problems with diatoms, then this would be something to look in to.

[rustybucket145]

I still wanna know who Mr. Wilson is....

[Insane Reefer]

Travis, do I get a gold star?


And for those who are curious, and lazy, the Ultimate DIY Rock thread (where a lot of this "info" is coming from):
http://archive.reefcentral.com/forum...2#post10595702

[HBtank]

Just one thing I have been thinking about....

I have seen DSB crashes attributed to the clumping that seems to inevitably happen in aragonite sand beds. Basically that if not properly setup and maintained, the clumping will occur. They have been theorized to hold hydrogen sulfide pockets and ruin DSB flow, possibly being th source of long term DSB crashes?

I have not read of this occuring with silica san beds. As well I have not personally experienced any sort of clumping in any silica tank I have had.

I have had them on a FOWLR tank I had with aragonite.

What do you guys think...? Maybe silica sand has a plus no-one has considered?

[Travis L. Stevens]

HBTank. The clumping is caused by the calcium percipitating out of the water in to the sand. Keep the Alk/Ca/pH/Mag in line, and you shouldn't ever have this problem. The Hydrogen Sulfide can happen in any substrate, mud included. Hydrogen Sulfide is formed as a result of the work of anaerobic bacteria. If you provide an anaerobic zone, then you will get hydrogen sulfide regardless of what you use.

[HBtank]

Yes, but isn't aragonite a reciever for the Ca precipitation? Silica is not, that is the difference.....

And I have read aragonite clumping is pretty common, and not confined to porrly kept tanks. I agree that precipitation can be definately reduced with parameters in-line, but can it be totally avoided?

It would seem 3-5 years (the times I have seen attributed to DSB crashes) is a long time and pretty hard to totally avoid any precipitation.

It seems that even over relatively short periods people are required to deal with precipitation on visible and mechanical receivers (on pumps, heaters etc..), and this is pretty commonplace?

As for hydrogen sulfide, all tanks DSB can form it.. yes. But I have seen the clumping attributed to forming dangerous pockets of it that are especially problematic when disturbed. And I have read that the precipitation facilitation the formation of the pocketrs due to reduced sandbed pore-flow which is essential to a healthy DSB in both import and export.

I just conencted the dots and was somthing I was considering....

[HBtank]

Oh, and I also would like to add aragonite replentishment to the cons of aragonite.

More costs, and disruptive IMO.

[Travis L. Stevens]

Yes, but isn't aragonite a reciever for the Ca precipitation? Silica is not, that is the difference.....

There is a difference there, but taking silica play sand's impurity issue, I'm sure there is something in there that the Ca will cling to, but at a much smaller rate than you would see in aragonite.

And I have read aragonite clumping is pretty common, and not confined to porrly kept tanks. I agree that precipitation can be definately reduced with parameters in-line, but can it be totally avoided?

Why wouldn't it be totally avoidable? Granted, the world isn't perfect and most people will slip up, but fwiw the two+ years that I've had multiple tanks with multiple substrates, I've never had a clumping issue. That doesn't mean I won't develop one 5 years from now or if ever. There are more reefers out there with clump-less sand than clumped sand, so I would worry about this as much as I would worry about diatoms and silicates.

It would seem 3-5 years (the times I have seen attributed to DSB crashes) is a long time and pretty hard to totally avoid any precipitation.

A sand bed crash is from pinned up nutrients to suddenly release themselves en masse. It doesn't matter what the substrate is made of, but the actual maintenance of the substrate that is important to nutrient release from sand beds.

It seems that even over relatively short periods people are required to deal with precipitation on visible and mechanical receivers (on pumps, heaters etc..), and this is pretty commonplace?

It's not really that common. You just hear about it alot because there are more people complaining about the problem than those speaking out and relishing that they don't. You see? Calcium percipitation isn't that common amongst those that have been in the hobby a while because they have learned to balance and maintain the Ca/Alk. It's usually those that are still learning that have a problem with it. Ca/Alk balance is a simple concept that is rarely taught to beginning aquarists, thus more people encounter this problem on a daily basis because the information isn't often available to read.

Oh, and I also would like to add aragonite replentishment to the cons of aragonite.

Once again, this is about balance. pH balance to be a little more accurate. If you maintain your pH at a decent level, you won't have it dissolve on you. You would need a near constant 7.8 pH or below to notice any substantial amount of aragonite loss over a period of time. If there was a problem with aragonite randomly dissolving with regulated pH, then our coral skeletons would dissolve away as well.