[everwater]

i think caulerpa gets a bad rap....i know the grape(racemosa) is known to go sexual but some of the others are really stable.
probably my favorite is c. prolifera...looks great in the display tank and i have never had it go sexual. still a possible tang food.
rhodophytom....is a red fern like algae that is usually too tough for most tangs to eat.....no always available in the hobby but a great deco algae.