Is this a cause for concern?

[knee]

Noticed these bubbles on the silicon of my 40B

[mynameisnobody]

@knee I’m assuming that’s a $1/gallon sale tank? 

[knee]

@mynameisnobody definitely aqueon but not sure if it was bought during that sale. I got this on Facebook marketplace for $30 with the stand. 
 

When I came to check the tank it still had fish and the owner told me it was used for 3-4 years. I didn’t check too much because I saw that it was still in use so I figured that it’s fine. The owner also said that it had water since day 1 and it was never emptied out after that. 

[mynameisnobody]

@knee it looks suspect, but I would just keep an eye on it. Most people think they are going to have some giant explosion which rarely happens. Usually for our use as hobbyists, it will almost always start with a leak. Just keep your eyes peeled and have a plan B. 

[CT_]

Could have been their since day 1.  If the bubbles don't change over time I bet you're fine.   The edge to face silicone is mechanical so small defects are okay if they dont progress.

[Biotope Biologist]

@CT_ is right. Aqueon are constructed in a way where small machine defects appear with how consistent those bubbles are along the silicone seal  I would be willing to bet thats where it came from and have been there since it was shipped. 

[knee]

Ok that makes me feel better. I'll observe if the bubbles get bigger after a few weeks.

Thank you @CT_ @Biotope Biologist