My dad has Alzheimers and isn't in a great nursing home. What should we do?

I'm going to make this short. My dad has been in a nursing home since one year. He has Alzheimers and his illness is progressing. Most of the staff is lazy, the floor isn't clean most of the time, there's a resident who keeps spitting on the floor (gross) in the dining room and the a lot of the residents look lonely and neglected. If we change location, my dad will be disoriented. He displays aggressive behavior at times so the staff doesn't want him there anymore. They're doing everything so that he leaves from there and want to transfer him to another home with people who display behavioural problems. Our family doesn't want that because my dad will be lost and may become even more violent. He always used to be so nice and soft-spoken, but the illness has changed him. What can we do? My mom, daughter and I go visit him every single night because he misses us so much.