Concerning glass

[milooo]

I have been using glass sculptures that I made (flame working) in my tank for as long as I have had it (not that long). It has recently been brought up that the glass may be leaching silica into the water. If this is true then the elements used in the colored glass may be leaching as well which would be extremely bad. If anyone has any info on this please let me know. I use borosilicate glass but info on any kind of glass would be greatly appreciated

 

[BigJim]

I don't believe glass leaches silicates.

 

[Mr. Limpet]

Glass 101

I was going to start a thread on glass aquariums, but milooo started this one first and I figured my thread would just be rolled into it anyway. So here's my spiel and take it on face value or discount it, you're choice. Besides that's what discussion forums are all about, right?

Glass is made of sand, sand has silica in it, melt it all together at 1200 degrees and you have a nice shiny, clear piece of glass with nearly 3/4's of it containing silica. Not sure how it can't leach it with that content (%).

"The resulting glass contains about 70 to 74% silica by weight and is called a soda-lime glass.[4] Soda-lime glasses account for about 90% of manufactured glass."

Glass - Wikipedia, the free encyclopedia

The only exception I can see is tempered glass has much less, since when we'd custom cut/ and temper smaller pieces in-house, the filtration system on the furnace did have a scrubber that dealt with burn off (silica?) from the glass while it was cooking. But that was a long time ago and can't confirm if silica content is reduced during the annealing process.

Toughened glass - Wikipedia, the free encyclopedia

New tanks leach silica from the surface until it's depleted, which IMO accounts for the (avg) 2 months of BA in a new tank.

Here's one more piece of info from a website that's one of my goto's on a regular basis.

"Silicates leach from new glass or new sand (glass and sand are silica based). It is not uncommon for new tanks to have algae growth due to silicate leaching."

Read more: How to Reduce Algae in an Aquarium | eHow.com How to Reduce Algae in an Aquarium | eHow.com

I've got more on acrylic tanks and their limitations, but since this thread is about glass, I didn't want to go off topic in order to answer HN1's question.

 

[xxwolfpackof1xx]

all my tankks are glass no BA also my sw has arognite sand been fuly cycled sence 5-21-2011 my fw no sand gravel runnin sence 11-28-2010 both glass tanks never had BA

 

[Mr. Limpet]

all my tankks are glass no BA also my sw has arognite sand been fuly cycled sence 5-21-2011 my fw no sand gravel runnin sence 11-28-2010 both glass tanks never had BA

Same for me on my brand new, all tempered glass 8g tank. Not a spot of BA which leads me to believe that tempered glass sears/seals the silica off/in (no facts, just observations).

My brand new 37g had 2 solid months of BA, once the conditions were right to feed it (17w->55w lighting upgrade) even with limited 4on/4off/4on light schedule. My used 29g is showing mild signs of it, but I do leave the lights on for 14hrs a day (55w), so I figure it's my own fault there .

As for your tank (or anybodies), there's too many variables to ever say you're "always" gonna get it and that wasn't the point anyway, but there's lots of threads with BA issues and I'd bet everyone of them has an experienced aquarist saying "every new tank gets BA" lol. I'd say I've read that phrase at least a hundred times in different threads and it'd be an interesting poll to compare BA in glass/tempered glass/acrylic tanks/new&used tanks/sand (type)/gravel etc to see if a pattern does reveal itself.

Your SW is still too new to say IMO and some say BA can show up, up to a year after a tank has been setup.

 

[xxwolfpackof1xx]

my sw lights are bein upgraded in the next few months from a 15w t8 to a 4x24w t5

 

[Mr. Limpet]

my sw lights are bein upgraded in the next few months from a 15w t8 to a 4x24w t5

Those are the exact conditions that set my BA off in my 37g. Is this a brand new glass tank (not tempered)? It is SW and mine was FW, but I'd be interested to see what comes of the big lighting jump. Of course, SW from some info I read (prepping for my 1st SW tank) actually covets silica. True/not true?

 

[xxwolfpackof1xx]

not sure to new to sw the tanks brand new standard 10 made by topfin so i think tempered?

 

[Mr. Limpet]

not sure to new to sw the tanks brand new standard 10 made by topfin so i think tempered?

You can tell tempered from regular glass really easy. Tempered glass will have a rounded (soft) edge, regular glass will have a square edge.

My 37g is all regular glass except the bottom (tempered glass waring sticker/"DO NOT DRILL" lol).

 

[xxwolfpackof1xx]

lol im assuming its regular then

 

[milooo]

It seems that if you use manufactured glass, or soda glass, it will have some leaching, but I don't think it is a serious thing. Another thing was glass made before the 18th century. Most all glass made after that point has a much more stable mix of silica and won't leach as much. I am fairly confident that the glass I am using will have little to no leaching because it is borosilicate and is used in lab equipment. The colors still may be a concern but I will test those out.

 

[Mr. Limpet]

It seems that if you use manufactured glass, or soda glass, it will have some leaching, but I don't think it is a serious thing. Another thing was glass made before the 18th century. Most all glass made after that point has a much more stable mix of silica and won't leach as much. I am fairly confident that the glass I am using will have little to no leaching because it is borosilicate and is used in lab equipment. The colors still may be a concern but I will test those out.

The 74% silica stat is using modern float technology, not 19th century. You're correct that the glass you're using isn't in the 90 percentile that aquarium glass is made from, it's what Pyrex® is made from, but it still has 70% silica in it's mix.

Borosilicate glass - Wikipedia, the free encyclopedia

 

[milooo]

yes, but it doesn't matter if it has a high silica content, it matters if it is accurate. if the glass has too much silica in the mix and it cannot be bonded with the other ingredients then it will leach more. it is all about the ratio of how much silica there is and how it bonds to form the solid structure of glass. so even if something has 70% silica, if it is mixed with the right ingredients it should not be leaching as much as glass with incorrect ratios.

of course some will leach, but this is only a minimal amount and is just because of the structure slowly decaying... i think (im no scientist)

 

[jetajockey]

I don't really know anything about the chemistry stuff behind leaching but I'm not so sure about the 'New tanks leach silica from the surface until it's depleted, which IMO accounts for the (avg) 2 months of BA in a new tank.' statement.

I mean you also have to account for silicates being delivered through the tap water and substrate material.

There's too many variables to narrow it down to the new tank glass doing it. One other reason is that I get 90% of my tanks in used condition, some very well used, lol. They all have diatom issues the same, there doesn't seem to be a pattern in these vs. new tanks.

I guess one way would be to use a brand new tank, and r/o or some kind of tested- silica-free water and no substrate and see what happens. Otherwise I don't know.

 

[mfdrookie516]

^Yep, a controlled test is the only way. Otherwise, it's just simply speculation. For all we know, silicates could be introduced via the air.

 

[jetajockey]

I think they are brought upon by the tooth fairy as a method of retribution for all of the ungrateful children she has delivered money to. The children lose a tooth, trade it in for some cash, and go buy more candy to lose more teeth. For shame.

 

[Mr. Limpet]

yes, but it doesn't matter if it has a high silica content, it matters if it is accurate. if the glass has too much silica in the mix and it cannot be bonded with the other ingredients then it will leach more. it is all about the ratio of how much silica there is and how it bonds to form the solid structure of glass. so even if something has 70% silica, if it is mixed with the right ingredients it should not be leaching as much as glass with incorrect ratios.

of course some will leach, but this is only a minimal amount and is just because of the structure slowly decaying... i think (im no scientist)

That's true and the other issue is that if you're taking pre mfg'd glass and recooking it, does the silica content diminish (unless you're adding more)? From what I've read, there is a constant decay of glass molecules (?) but the micron loss is so minuscule as to almost be undetectable (at least not without some high priced laser based measuring device of some sort).

One way to test is to get a silicate test kit, get a base reading (fresh water?) then add your decco to it and see over time (days, weeks, months?) if the silica count raises significantly.

Silicate Multi Test Kit

 

[milooo]

yeah i might actually do this. my mom bought me a whole bunch of beakers and sciencey equipment from a flea market that i really had no use for.

 

[Mr. Limpet]

I don't really know anything about the chemistry stuff behind leaching but I'm not so sure about the 'New tanks leach silica from the surface until it's depleted, which IMO accounts for the (avg) 2 months of BA in a new tank.' statement.

I mean you also have to account for silicates being delivered through the tap water and substrate material.

There's too many variables to narrow it down to the new tank glass doing it. One other reason is that I get 90% of my tanks in used condition, some very well used, lol. They all have diatom issues the same, there doesn't seem to be a pattern in these vs. new tanks.

I guess one way would be to use a brand new tank, and r/o or some kind of tested- silica-free water and no substrate and see what happens. Otherwise I don't know.

I'm 100% behind you on that first part of your statement . Yep silica from water, from the items used to deliver the water, the substrate, the decco, tools used in the tank, ad nauseum all play a part in it.

I guess the best test would to setup 2 identical systems, one glass, one acrylic and see what happens. Jeta, get out your tooth fairy money, I'll let you run that one and report back in 6 months lol.

I think they are brought upon by the tooth fairy as a method of retribution for all of the ungrateful children she has delivered money to. The children lose a tooth, trade it in for some cash, and go buy more candy to lose more teeth. For shame.

 

[jetajockey]

yeah i might actually do this. my mom bought me a whole bunch of beakers and sciencey equipment from a flea market that i really had no use for.

are they glass?