Hi, I've got a 12 gallon tank with live rock, a clown, 2 damsels, and 2 peppermint shrimp. I want to get a sea star. When looking at the less expensive, hardier sea stars, they all look to grow up to 6 inches. This seems far to big for my tank. I'm wondering if anyone knows of a sea star that is relatively hardy that will not out grow my tank. Thanks for the help.