Is the silicone starting to fail? Please Help!

[Coral Keeper]

Hey everyone, I have a 120 gallon 4'x2'x2', the tank is about 5 years old or so and noticed the silicone is discoloring? Any thoughts on why? Is the silicone failing? Do I have to replace the tank?

 

[T-J]

Hard to tell in that picture. Can you take a pic straight on the edge with the silicone that between the two panes of glass? So we can see the state of the silicone between the two pieces.

 

[Coral Keeper]

I'll take some from inside of the tank once the lights come on, you can see some discoloring when you're looking into the tank..

 

[vetteguy53081]

Silicone does not shrink to this extent. Dont see it being an issue BUT do keep and eye on it.
It is fortunate that it is at the top and can easily be resealed if ever needed especially if it would seep/leak

 

[tehmadreefer]

Could be anything but the thought of 120g if saltwater on the floor wouldn’t be good.

 

[NowGlazeIT]

Is it loose? Flappy even? in my rimless when I would use a razor blade too close to the edges, damaging the seams. I loss the dark black color and could stick a finger nail behind the silicone. It held water for 2 years no leaks.