bubbles on surface

Question
I recently bought 3 black Tetras and a small 1 gallon tank with filter.  I thought I put everything together accordingly but there are bubbles forming on the surface.  My question is, Why?  Am I doing something wrong, does my tube need to be submerged out of the water instead of 1/2 inch below the surface or is my water not ready or is this normal.  Please Please  let me know.

Answer
Bubbles are bubbles. It is water bubbles happen and there is nothing wrong with it.

However, that is probably the only thing that isn't wrong with your tank.

A 1 gallon is not big enough to keep any fish. The company's sell them to make a profit off people who have no idea what they are doing. In some European countries, you would be fined for keeping those poor fish in that size tank.

Black tetras need 20 gallons minimum, and a school of at least 6.

I would either return the fish, and get shrimp instead. Or return the tank and get a 20 gallon.