Bubble build up at the top of my tank? Also heater not working.

[Riley Pasha]

Has anyone else ever had a bubble build up in the top of their tank? the bubbles are building up in the corners of the tank. Also my heater that I use for my water changes isnt working for some reason. It is the kind of heater that u turn to the + side then it heats up the water but for some reason after having it in for an hour or so it was about 75 degrees and the heater stopped functioning and wouldn't heat up the water. I also noticed only the top of the water was warm for some reason. The orange light indicating the heater working isn't on and I am not sure what to do. I tried using a different outlet with no success.

I attached a picture of the bubbles.

 

[melypr1985]

What is the heater set at? Can you tell us the brand? Also do you have a surface skimmer on the tank? Either from an overflow or an HOB skimmer? One last one.... That powerhead is pretty close to the top of the water.... is it creating a "whirl pool" which in turn shoots bubbles out of the power head? Without a way to skim the surface, those bubbles could collect on the surface of the water.