If it is Dino and you are just starting your tank. Turn your lights off for three or four days. If it is Dino the snails will start to do. DO NOT do water changes if you realize it is Dino's. It will make it much worse.
Nothing will eat it. Just kill lights, raise alkalinity, and watch it dissappear.
I also have a Sea Hare and just noticed some bryopsis, hope it goes to town on it. Honestly, one of my favorite tank inhabitants ever. So much personality and if you like big backs, well . . .
Lee
Lee