Which type of caulerpa are you looking for? I understand keeping it on for 24 hrs etc, (and I have in my fuge) however, they do go sexual regardless when a runner dies. Not only does it give off the nitrates and phosphates it absorbs, but then the toxicity becomes a problem. I have both chaeto and caulerpa in my tanks and I've had caulerpa go sexual (from my display tank) with both nothing happens and it went toxic and killed the whole tank. And I have had chaeto not grow, spinning, not spinning, different colored lights, etc.
So what did I learn? Well I thought about it and I realized that depending on how much bioload I had and how good of a skimmer I had, that would affect the need for one or the other. For me, my bioload for some of my tanks are extremely small and the skimmers can help with the bio matter and then the chaeto would take up the nitrates and phos. On my bigger bioload tanks, I use caulerpa (24hrs) and have decent skimmers. When you have too good of a skimmer and use macros, I find I'm starving the macros for nutrients, and therefore they go sexual and its hell from there.
Just my opinion, and while I understand most of my fellow reefers and much more knowledgable, I like to contribute in my experiences bad and good. But ultimately, in the whole bigger picture we all learn by our experiences. So if you want some caulerpa Lmk.
I think seahorses are cool.