240 gallon - glass cracking?

[CMC]

Some of you may remember us buying our 240 gallon tank earlier this year. Well we're wondering if we have a problem now.

In the past 2 weeks we've noticed very tiny cracks in the front glass starting to develop (almost like a crack in your car windshield but much much smaller). There are 3 vertical rows going down the glass - 2 rows in the middle about 6" apart, and one on the left side of the tank. All together we have counted about 50-60 tiny cracks. They all appear to be on the inside of the tank glass, none on the outside. The glass is 1/2" thick. We've also noticed a couple on the back glass as well. There are none on the side glass.

We put dots on the outside of the glass with a marker where each little crack is so we can keep track of any new ones. The tank is filled with water and 10 angel fish.

Our gut feeling tells us that these are tiny stress cracks and it's just a matter of time before the tank starts to leak, or worse, niagra falls. We're wondering if the vibration from the trains (we live near a RR track and it vibrates the house sometimes) could be causing it. The tank should be well-cushioned though. The stand sits on top of a rug with padding underneath and the tank is sitting on top of a styrofoam cushion (came with the set-up) on the stand.

Any glass experts out there? We tried to take a picture of them but the cracks are too small.

Thanks!

 

[pnyklr3]

Let me start by saying I'm not a glass expert. I do, however, have a 55 gallon that won't hold water. The glass isn't cracked, but the little piece of plastic that goes from the front to the back is broken. THat little piece of plastic actually keeps the glass in place (I was astounded by this). The result is that the front (or back depending on how I have it) bows out when it is partially filled, and therefore will not hold water. I am not suggesting that this is your problem, but that sometimes small things can have a big effect on the glass. Did you buy the tank from your lfs? Most tanks have a lifetime warranty.....but hopefully it won't come to that.

 

[gaya]

Wow what a bummer. I'm so sorry for you. Something like this is my biggest fear.

Hope this is not totally off the wall but if you can't return the tank maybe you could call a glass company. Do you have a giant glass out there? Ya know, the places that come to your car to fix windsheild cracks. Maybe they could use an aquarium safe chemical when fixing it.

good luck

 

[samthefishman]

is this tank second hand?
they could actually be straches... my fish scratched up my 23gal.
Well whatever the prob i hope yous can deal with it.

 

[CMC]

We bought the tank from an aquarium dealer on Ebay. We picked up the tank at his factory. In hindsight, we should have asked about a warranty when we bought the tank. We looked at his website again and it doesn't say anything about a warranty but we're going to contact him about it. We are also going to get in touch with a local glass company today to see if they can come out and look at it. This sucks
I'll let you y'all know what happens.

 

[black convict 0331]

if the tank is made by all glass aquariums then thiers is a lif time warinty

 

[canarsie11]

Even though person you purchase does not have warranty. The manufacturer more than likely would stand by tank

 

[Waterloo Kid]

Warning slightly technical!

Glas will only crack if it is being stressed in TENSION, that is, pulled apart. With the water pushing out from inside the tank the inside of the glass should actually be in COMPRESSION (pushed together). If any cracks started then they should start at the outside and work inwards, not the other way around. If the top of the aquarium is not fully restrained by ties (like pnyklr3 stated earlier) it could be bowing out which could cause the glass to bend in such a way that the inside face of the glass is under tension. This (internal cracking) would only happen in tall, wide tanks though, and the cracks would be a series of horizontal cracks.
Glass, being very brittle, is more likely to let go in one very wet episode. I think it's unusual for glass to gradually crack, that's not how it works. I'm not a glass expert, I design in steel and concrete but these are my gut feelings. There may be something else going on with internal stresses that I cannot comment about.
A 240 gallon tank must have top restraints to prevent bowing and reduce stresses on the tank corners (going back to what pnyklr3 said again). If you've taken these off or there aren't any then put some on NOW.
I'd check to see if these marks aren't infact flaws in the surface of the glass. Thinking about it, they could be cracks caused by flaws in the structure of the pane in which case I'd be onto the manufacturer.

Hope that helped a bit,

WK

 

[Genki]

About not having a warrenty...You're still safe if it was a problem with the manufacturor. Every thing you buy (unless sold 'as is') has an implied warrenty on it, meaning that a product has to preform as it should. (a toaster toasts, a fish tank holds water). It is a law (at least in the U.S.) so you can still take it back if it's not a result of you doing something funky to it.

 

[Great Lakes]

I am beggining to suspect that you may have a laminated glass tank. This is where a maker sandwiches shets of glass together to achieve a desired thickness.

This at least would be a logical explaination of why you can see cracks, yet have not seen catastrophic failure.

I do not see any recourse but to immediately empty the tank.

The "Glass God" always finds the most entertaining time to flood your room around the 3am hour.

GL

 

[ste2k3]

I work in the trade. If it is normal float glass, then I don't think there are cracks, they are probably scratches as if they were crack, the crack would run down the tank and you have a tidal wave on your hands-I'v seen it happen. Is the tank braced? if it is made from toughened glass then I'm not to sure as this may well happen? toughened shouldn't really be used for all glass aquariums. also, if it were to crack, then the crack should go all the way through the glass from front to back.

ste

 

[fufanu360]

i really dont think 1/2 inch glass is big enough for a 240 gallon tank, my dads 66gallon had 1/2 inch glass