I have a question concerning my betta?

Hey guys, I have thinking about re-homing him. He currently lives in my Baby BiOrb (15 Litres) and I think the bubbles are preventing him from properly reaching the surface. I have already tried clipping the air pump wire thing but that just decreases the filter performance. I am thinking of putting him in a normal rectangle aquarium. What do you guys think? He has been living in the BiOrb for over a month now. Thanks.