What are the chances that the caulerpa will go sexual? I've read of dozens of seahorse tanks that use it in the main display. I don't recall reading about any specific dangers of it going sexual in those tanks considering they do have a normal light cycle. Maybe the danger is if a large amount of caulerpa goes sexual all at once. If used in a fuge I suppose the purpose would be to have a large amount for nutrient export. How much do you have in your tank? Maybe if you don't have that much you could switch to an on/off cycle and keep your zoa frags down there. I think that is the main reason Cheato is popular.