I just bought a gsp frag along with a zoa , all my corals doing good but this new gsp wont open?, it has a little brittle star under it that came with it? Where do i need to move in the tank for it to open
GSP also tend to get really angry and close up for a few days if they've been irritated. A tank move is definitely an irritation event. Give it a little more time I'd say.
GSP will take many conditions but prefers strong light and high flow...I have it at both the top and bottom of my tank. Just make sure to put it somewhere where it can easily trimmed back.