I wouldn't reseal it then. that requires actually seperating the panels which is not normally done. normally just the excess silicone is removed and the factory seal between the glass panels is left intact. then more silicone is put over top of the joints without seperating the panels themselves. those bubbles have probably been there from the intial tank seal as it was built. the only time they are a concern is if when you press on the glass, you can see the bubbles move. if they don't, don't worry. you saw it filled with water right? I would just leave it if the rest of the seals look in good shape.