Ok so heres the situation...
Today I stopped at the lfs and found what they called a red general starfish for $30. It is about 5 inches from one side to the other. Before I bought it, I looked through some of the stores books and read up on it and it seemed like a good candidate for my FOWLR tank. Its a meat eater, meant to be kept away from corals, but doesnt have any harmful characteristics that might harm anything in the tank like poisonous spines or anything. So I brought this thing home, acclimated it, and dropped it in the tank.
Heres what he looks like (Random internet pic):
So I watched him for a while and he just sat there not moving. Now in this tank I have a 2 inch scarlet hermit crab. I did some other things around the house and then came to find the starfish slowly creeping his way over the back of the hermits shell like it was going to consume him and eat him. I watched for a little while and the crab finally noticed the starfish and started trying to walk away. Over time the crab just kept moving closer to the other side of the tank and that starfish just kept following him. I knew there was going to be a problem right then. So later I was talking on the phone and I looked over at the tank to find the starfish had totally pissed the crab off and the crab was on top of him with one of the starfish's spines in between his pincher claw ready to clamp down. I immediately shot my hand into the tank and grabbed the crab and moved him to the other side of the tank and that is where we are at right now.
So I am wondering if anyone else has had experience like this. Did I make a bad compatibility decision? I dont want to take it back if I dont have to, but I definately love my crab more than the starfish and I dont want to lose $30 if the crab wins. What does everyone think I should do?