Are these air bubbles?

[Jeff]

A couple of months ago, I bought a brand new 90 gallon Marineland tank. Future home of my Discus tank. 

Anyhoo, I was testing it tonight, and filling it up, to test for any leaks. 

These showed up in the corners - all four. Any ideas? Are they just bubble pockets?

 

[KBOzzie59]

Do they come off and float to the surface?

[Jeff]

37 minutes ago, KBOzzie59 said:

Do they come off and float to the surface?

They didn't come to the surface. But, are gone now that I emptied the tank. 

I'm not really worried...but never seen this before in a tank. But, kinda low key nervous that they'll be there when my tank is set up?

Then again, I've never had a tank with black silicone before, like the Marinelands have.

Edited November 11, 2020 by Jeff

[tolstoy21]

Could be condensation if there was moisture trapped in an air pocket air in the seam when it was sealed. If you added cold water to the tank when you filled it, this might have caused that.

I’ve seen that with a bottom cross brace when leak testing a tank.  Air trapped in the groove in the cross brace (which was pressed firm to the glass after filling) had beaded up on the bottom glass. Had me second guessing the tank for a week. 

Just leak test it longer to feel more sure. Test the corners by wiping gently with a paper towel once a day or so. That should give you an indication if it’s leaking. I’d do that for piece of mind before stocking it.

[Jeff]

Yeah, I filled it up with cold water. No sense in wasting warm water just for testing.

Thanks. This gives me piece of mind. I'm more at ease.