If you mean Christmas Moss, yes, you can trim it with scissors or pull parts out of it.
I guess it depends how you have it set up. If you have it wrapped around branches or rocks, you'd be better off to trim it with scissors or you might just pull the whole thing loose. If it is just growing somewhere to a giant ball, you can rip it apart.
When you trim it with scissors, you almost always end up with lots of little pieces floating around the tank. They settle somewhere and grow new Christmas Moss colonies.
I guess it depends how you have it set up. If you have it wrapped around branches or rocks, you'd be better off to trim it with scissors or you might just pull the whole thing loose. If it is just growing somewhere to a giant ball, you can rip it apart.
When you trim it with scissors, you almost always end up with lots of little pieces floating around the tank. They settle somewhere and grow new Christmas Moss colonies.