My tank is starting to go through the ugly phase and Algae is becoming plentiful in my tank. I am looking at getting a tang. The tangs I am interested in are the White cheek, Purple, and Atlantic Blue Tang. I have always wanted a purple tang, but all 3 are gorgeous fish so I feel like I can't go wrong. For a tank that has been running for 4 months what would be my best bet for a good hair Algae eater. Any advice would be appreciated.