Tractor supply I believe carries the liquid poultry vitamins. I'm not sure if it will help or not but give them a try. I will tag a few people who know chickens, perhaps they can comment on the air bubble.
@Wyorp Rock , @Eggcessive , I know it's a poult, but maybe you have an idea.
Are you using heat there? It definitely doesn't need extra heat anymore. I'd try the vitamins. That's about all you can do. Turkeys also need company, preferably another turkey.
Is it made for turkeys or gamebirds? A chick starter isn't formulated for the more rapid growth in turkeys. Is this a broad breasted poult or a heritage white? Generally it's recommended to feed a 28% protein game bird ration for the first month, than you can step down to 24% after 4-6 weeks.