Yes, sand sifting stars do tend to starve to death in tanks, moreso in ones as small as this one. Since the tank is so recently set up, there's likely very little for it to sift out of the sand at this point. It would be much better suited in an established tank that's at least 2 - 3x the size as this one, with a DSB. If you plan on keeping it, the star would benefit from being fed regularly to help it survive. Hopefully, it won't cause a rock slide in your tank as it moves about and digs around.
Was your yellow tang bitten by something? It looks like a small chunk is missing out of its dorsal fin near the front. Similarly, the yellow tang isn't going to do well in a tank this small for very long.
Was your yellow tang bitten by something? It looks like a small chunk is missing out of its dorsal fin near the front. Similarly, the yellow tang isn't going to do well in a tank this small for very long.




