Burp him buddy, i had to get very aggressive to my MBU to get the air out, he got gased up from the algae waffers i was feeding my Turtle, he'd steal some and then he'd get "fat" and drag his belly on the bottom or swim all weird like your gf said " a blimp crashing" lol, my guy was so bad that either it was gonna die probably if i didn't get aggressive with the burping, it took 3-4 times over the course of an evening then when i woke up he was back to normal!!!! GL let us know how things go