Tiny hairline crack on glass

[Maximus146]

Not sure if you can tell by the photo, but I just noticed a tiny hairline crack on the outside of the tank. It’s barely visible and hard to even feel. It’s near the top of the tank in the corner. Should I be concerned and if so, what should I do about it?
Thanks!

 

[Milingu]

Is it really a crack or just a scratch?

 

[jjohnwm]

As Milingu suggested, I would try to determine if it's a scratch or a crack. And if it's a scratch deep enough to determine this visually, then I would treat it as a crack.

If it was always there, I would empty the tank and not use it until that panel has been replaced. And if it is a new development since you set the tank up, I would empty right now, not this weekend or next month or whenever I have time...but right now. This only seems paranoid to people who have not experienced a catastrophic tank failure in a finished area of their homes. I have.

If it is on a tank in a basement fish room, i.e. not necessarily a display tank and not capable of wrecking your house, I might try repairing it by cutting an identical size piece of equally thick glass and then siliconing this directly over top of the cracked pane, effectively giving you a double thickness pane on that surface of the tank. I tried this once, and it held up for a couple of years, until I tore the tank down for other reasons. It looks terrible; mine was 24 x 24 inches, and the silicone was a thin layer over that entire area. But, it held water for a couple of years and might have lasted longer given the chance; it was more an experiment than anything else.

 

[Milingu]

[...] And if it is a new development since you set the tank up, I would empty right now, not this weekend or next month or whenever I have time...but right now. This only seems paranoid to people who have not experienced a catastrophic tank failure in a finished area of their homes. I have.

Totally agree.
I once had a tank crack in the middle of the night. I was lucky in three ways. I was at home. I could hear it crack and the water was leaking out quite slow. So I could prevent major damage. But I aged a whole year in few hours trying to catch the leaking water with buckets and towels while getting the water out of the tank as fast as possible without icreasing the crack.

 

[Maximus146]

Is it really a crack or just a scratch?

That’s what I was thinking also that it might just be a scratch. Would you be able to feel a scratch like that?

 

[Maximus146]

As Milingu suggested, I would try to determine if it's a scratch or a crack. And if it's a scratch deep enough to determine this visually, then I would treat it as a crack.

If it was always there, I would empty the tank and not use it until that panel has been replaced. And if it is a new development since you set the tank up, I would empty right now, not this weekend or next month or whenever I have time...but right now. This only seems paranoid to people who have not experienced a catastrophic tank failure in a finished area of their homes. I have.

If it is on a tank in a basement fish room, i.e. not necessarily a display tank and not capable of wrecking your house, I might try repairing it by cutting an identical size piece of equally thick glass and then siliconing this directly over top of the cracked pane, effectively giving you a double thickness pane on that surface of the tank. I tried this once, and it held up for a couple of years, until I tore the tank down for other reasons. It looks terrible; mine was 24 x 24 inches, and the silicone was a thin layer over that entire area. But, it held water for a couple of years and might have lasted longer given the chance; it was more an experiment than anything else.

How do I determine if it’s just a scratch?

 

[Milingu]

Can you feel it from both sides of the glas? If yes, then it is a crack.

 

[Maximus146]

Can you feel it from both sides of the glas? If yes, then it is a crack.

Ok I was thinking maybe that’s how I am tell if it’s a crack or not. No....I can only barely feel it on the outside of the glass

 

[Gourami Swami]

How I would treat that depends on a few things. How big is the tank; and where is it located, most importantly. In a 20 or 30 gallon in a garage or somewhere with a floor drain, I might not worry about a crack in the top of the tank. 40 gallon +, or any size in a room of the house with wood floors and no floor drain etc., I wouldn't risk it. Brand new tank will be 1/100th the cost of replacing wood floors. If you don't own the house and are renting, could open you up to lawsuits even.

 

[Potato Patatto]

The shape (path), length, and placement tell me that’s a crack and not a scratch. I would not risk it, if you don’t have another tank on hand I would at the very least lower your water 3-4 inches below that line immediately and go get a replacement tank.