my tank is 92g, yes 24 not recomended, may get away with a flower type. They don't move around, they will foot into a rock and stay. But not sure this is a new animal of mine and not sure how big they get.
Just to give you and idea my little cute green carpet only was 5 inches across when I bought him. He is now 16+ inches in Dia a regular diner plate is only 12 inches in dia!! only 1 year later. Still even in my tank he takes up alot of room, and I don't place anything around him, he has atleast 8 to 9 inches of space around him so he can spead. Before he found his favorite spot he moved all over my tank, messing up all kinds of things, yes he moved rocks! Now he has been in this one spot for about 6 months, he likes the soft flow, and is footed into a large cave.