It is definitely reef safe and is a good scavenger, not so much of algae, but of extra bits and pieces of food. If it is going into your 10g nano, you might need to target feed it once in a while to make sure it doesn't go hungry. It is a bit big for such a small tank, mainly just because of its dietary requirements. Might I suggest "sexy shrimp" if you're looking for a fun nano-compatible crustacean?
Saltwater Invertebrates for Marine Reef Aquariums: Sexy Anemone Shrimp
I love mine. She lives in my xenia and forages all day long. Lots of fun to watch!