I have a two-spot tang (Ctenochaetus binotatus) in my tank that is a great fish! Cool looking and feeds on detrius and unicellular algae. Will eat film algae off the glass and scoop up mouthfuls of sand. Hands in the tank and he likes his sides rubbed. Looks close to kole except for blue rings around the eyes instead of yellow. The longnose is still a iffy reef safe fish and difficult but from what I have read they are a bit more hardy than CBB's. Link to picture of two spot tang:
http://www.amonline.net.au/fishes/fi...binotatus2.jpg