tank cracked

[uberunce]

today i went to check on my 30g and found a huge crack in it. on the side glass it went from the top to bottom (directly in the middle). im trying to figure out how this happened.
its a somewhat old tank a buddy gave me with a canopy and light (when i first got it there was nothing wrong with it). the canopy didnt fit all too correctly but i didnt mind as long as it covered the top. today i found it 'fitting' in place which i believe my pops took into his own hands. could this added pressure (squeezing a canopy that didnt fit properly, and forcing in place) eventually make the tank crack?

 

[repair]

it could..... what kind of a stand does it have?

 

[sweeTang21]

tanks generally crack because of a bad stand or a chip in the glass. in older tanks its no surprise that the silicone sealent becomes weak with age causing the glass the pull apart in certain areas. although this is a rare occurance it should still be considered. stands need to be level on all sides, otherwise you get a broken tank. generally if one corner sits lower then all the rest it is putting a lot of stress on the glass. silicone is very flexible and most of the time allows the glass to move in small distances but not always the case. glass can bow about 1/2 before it cracks. you said it was right down the middle, this tells me its an issue with your stand.

 

[uberunce]

stand i have is just a metal stand my pop fabricated. ill have to check again if it is level.
thanks for the replies.

 

[Liam]

My guess is that it's not the canopy, if it was i recon the coners where it had been siliconed would've given way first.

 

[sweeTang21]

yeah just check for the steel having a bend halfway through the lenght of it. all it takes an 1/8 inch difference lower then the halfway through the lenght. i hope you understand what im tryin to say lol. also if theres a weld thats sticking out on the top then that would more then likely were it would be.

 

[repair]

I have started using the pink instalation board on my stands just to be safe

 

[uberunce]

the crack is actually on the width side. theres no bend from what i can see, nor welds. i guess just an old tank.