A little worried.. Silicon separating from glass?

[Hentz]

Hey guys,
Recently I was cleaning my glass and realized I had this random square odd spot in my silicon. Tank is a 120 Gallon tank with 3/8” glass. It’s 5 years old, I’ve owned it for the past year. It was well kept prior and never bumped or anything from what it seems. It’s also eurobraced.

Tank is standard 48x24x24 and this spot is 18.5” high on the right front panel of the tank.

 

[lapin]

To clarify. You are asking about the rectangle that looks to be on the outside of the seam. Its not the reflection of a tab holding up your mp40?

 

[Hentz]

To clarify. You are asking about the rectangle that looks to be on the outside of the seam. Its not the reflection of a tab holding up your mp40?

Correct, sorry. And no it is not, I don’t think so. I didn’t even think about that.. I’ll take my MP40 off later and see if that’s the case. Doubtful though.

 

[Hentz]

Checked, definitely not the powerhead reflection.

 

[dede]

It looks like a piece of residue from tape to me. Maybe the previous owner was taping cords to that spot. Can you remove it all with vinegar?

 

[Hentz]

No it’s inside the glass and silicone. I physically cannot feel it or get to it.

 

[Daniel@R2R Verified Admin]

Looking at it, it does look like a piece of something that was there but has been removed...but that still might make me nervous. Maybe someone with more experience on tank repair will weigh in. #reefsquad #DIYwizards

 

[TheEngineer]

Some tanks used to have tags under some superficial silicone to hold them in place. That looks fairly deep though. It is also on the outside of the seam, which is odd.

Not sure that hurts the structural integrity to be honest.

 

[Brew12]

It looks like a piece of residue from tape to me. Maybe the previous owner was taping cords to that spot. Can you remove it all with vinegar?

I tend to agree with this. The lines seem awful straight. It could be a lack of UV degradation from when tape was applied there that you just noticed.

If it were my tank, I would take a white board marker and outline the mark. That way you can check it every day to make sure it isn't changing size or shape.

Edit: The reason I feel this is based on what looks to be similar marks extending to the back of the glass where there would be no silicon.

 

[Hentz]

I do tend to notice that a lot of tanks with silicone separating seems to be not so straight like mine is. They seem very random and not so perfectly shaped by any means.

Still has me a little worried though.. Hopefully it is just left over tape residue.

Thanks everyone for the replies. If anyone has anymore ideas, let me know.

Until then, I'll be continuing to monitor it day by day.

 

[Stigigemla]

Save the photo and make new pictures to compare after a month or so. I believe its been there all the time but as soon as You are concerned about it it appears to be bigger...

 

[Zephrant]

Who made the tank? Looks to me like a small spacer was used. Either left in (made of clear silicone), or removed and back-filled after curing.

That's the only one you can see in the entire tank?

 

[Hentz]

Who made the tank? Looks to me like a small spacer was used. Either left in (made of clear silicone), or removed and back-filled after curing.

That's the only one you can see in the entire tank?

The tank is made by Visio. It’s great quality but by no means top quality.

That is the only one I see in the entire tank. I’ve checked all other corners to make sure.