My Empty Tank Just Cracked

[Traffik]

A few days ago I emptied my AquaOne tank.
Drained all the the water and scooped out all the sand.
There was some wet sand left in the bottom so I left the tank to stand for a couple of days hoping it would dry out so I could hoover it out.
It didnt dry out enough so I put a small fan heater in the tank to blow warm air around and dry the sand.
It worked, the sand dried and I hoovered it out, all good.
2 days later, all of a sudden, crack! Right across the front of the tank (bowed glass).
I dont understand it, surely it cant be a temperature issue, the heat from the blower was fairly hot, yes, but toughened glass should be able to take that. And 2 days later... surely not.
 
Anyone got any ideas?

 

[DreamertK]

Oh noooooo. What a beautiful tank!
 
The internet says:
 

 
Spontaneous glass breakage is a phenomenon by which toughened glass (or tempered) may spontaneously break without any apparent reason. The most common causes are:

• Minor damage during installation such as nicked or chipped edges later developing into larger breaks
• Binding of the glass in the frame, causing stresses to develop as the glass expands and contracts due to thermal changes or deflects due to wind
• Internal defects within the glass such as nickel sulfide inclusions
• Thermal stresses in the glass
• Inadequate glass thickness to resist wind load

 

[ShinySideUp]

No idea but lucky it went while empty.

 

[Traffik]

 
Oh noooooo. What a beautiful tank!
 
The internet says:
 

 
Spontaneous glass breakage is a phenomenon by which toughened glass (or tempered) may spontaneously break without any apparent reason. The most common causes are:

• Minor damage during installation such as nicked or chipped edges later developing into larger breaks
• Binding of the glass in the frame, causing stresses to develop as the glass expands and contracts due to thermal changes or deflects due to wind
• Internal defects within the glass such as nickel sulfide inclusions
• Thermal stresses in the glass
• Inadequate glass thickness to resist wind load

 

 
Hmm, interesting...

No idea but lucky it went while empty.

 
Yeah that's exactly what I thought when it happened!!

 

[Ch4rlie]

How annoying and shame it happened on a nice tank!

Most likely due to changes in temperature, glass and stand expands and contracts more than you think especially in cooler weather conditions. Traffik's post pretty much explains this to an extent.

The fact you emptied the water out meant the glass and stand suddenly has to contract due to less pressure and weight of water.
The cool water is gone and replaced by completely different air temps, the air heater probably did not help your cause and took a day or two for the stand and glass to react unfortunately.

A shame that's happened

 

[Traffik]

How annoying and shame it happened on a nice tank!

Most likely due to changes in temperature, glass and stand expands and contracts more than you think especially in cooler weather conditions. Traffik's post pretty much explains this to an extent.

The fact you emptied the water out meant the glass and stand suddenly has to contract due to less pressure and weight of water.
The cool water is gone and replaced by completely different air temps, the air heater probably did not help your cause and took a day or two for the stand and glass to react unfortunately.

A shame that's happened

 
Right, so the chances are it wouldn't have cracked had I left it setup??

 

[Ch4rlie]

It might have happened anyway to be honest but no way of knowing for sure, really, it's one of these things that unfortunately happens am afraid!

There have been other instances where this has happened in very similar circumstances like yours!

Just gotta bite the bullet and buy another tank or perhaps replace the glass if you're any good with that sort of thing.

Sorry!

 

[bodge99]

Hello,
 
You appear to have "normal glass" here.. this is indicated by the propagated crack. I'd guess that the heat differences from the front to the rear glass surface have caused some internal glass flaw to propagate. This flaw may have been of microscopic size.
 
TIP. It's not the heat that dries something out so much as the actual airflow across it. The process of evaporation takes energy from the item, so lowering its temperature. Warming a substance does allow the evaporative process to continue more rapidly, but the airflow is the important factor.
 
When drying any glass structure or anything involving wet electronics, play safe and use cold air only.
 
Sorry for your loss.
 
Bodge99.

 

[Traffik]

Hello,
 
You appear to have "normal glass" here.. this is indicated by the propagated crack. I'd guess that the heat differences from the front to the rear glass surface have caused some internal glass flaw to propagate. This flaw may have been of microscopic size.
 
TIP. It's not the heat that dries something out so much as the actual airflow across it. The process of evaporation takes energy from the item, so lowering its temperature. Warming a substance does allow the evaporative process to continue more rapidly, but the airflow is the important factor.
 
When drying any glass structure or anything involving wet electronics, play safe and use cold air only.
 
Sorry for your loss.
 
Bodge99.

Cool thanks

It might have happened anyway to be honest but no way of knowing for sure, really, it's one of these things that unfortunately happens am afraid!
There have been other instances where this has happened in very similar circumstances like yours!
Just gotta bite the bullet and buy another tank or perhaps replace the glass if you're any good with that sort of thing.
Sorry!

Yeah I already have another tank setup.
Its a diy project, alcove tank.
I built a sturdy frame using 70mm batons and 18mm ply shelf.
Stuck a camping mat down to iron out the imperfections and stuck a 4ft tank on top.

 

[jasonh_000]

A few days ago I emptied my AquaOne tank.
Drained all the the water and scooped out all the sand.
There was some wet sand left in the bottom so I left the tank to stand for a couple of days hoping it would dry out so I could hoover it out.
It didnt dry out enough so I put a small fan heater in the tank to blow warm air around and dry the sand.
It worked, the sand dried and I hoovered it out, all good.
2 days later, all of a sudden, crack! Right across the front of the tank (bowed glass).
I dont understand it, surely it cant be a temperature issue, the heat from the blower was fairly hot, yes, but toughened glass should be able to take that. And 2 days later... surely not.
 
Anyone got any ideas?

 
wow i never took into consideration what effects it would have on a large tank to immediately drain out the water. maybe 20% should be drained out every 2 hrs?

 

[ShinySideUp]

I sometimes wonder if I strain my own tank when I do a water change. It's 640 litres and I change 300 litres at a time each week meaning that the load varies considerably for an hour or so.

 

[DreamertK]

Usually people try to match the new waters temperature with the old waters temperature. Water actually makes the temperatures around it more consistant.