I bumped the edge of mine with one of those 6 cell mag flashlites and chipped it right in the seam. Its a tiny chip though, and its held water for at least 2 years. What gets me though is when I first bought the tank and got it home and took it out of its packing, I noticed two big honkin scratches on the front glass, one about 3 inches long, the other about an inch and a half. Dummy me I didn't take the tank back for a replacement. I had already waited on this tank for a month and a half. Long story short, I never even notice those scratches anymore, they are there if I look for them, but I'm so used to them I see "around" them.
. Anyhoo, you DID pay good money for that tank, were I you, I'd take it back and get another one. If it DOES leak, the manufacturer might turn around and say the chip was your fault and not honor the warranty, you never know.