[Subsea]

Yes to both questions.

I grew Caulerpa Prolifera and Caulerpa Paspoides, IMO the most gorgeous of the feather caulerpa, under intense light from 1000W 6500K metal halide in a 150G tank. It looked fantastic and grew like gang busters. My bio load was insufficient for nutrient uptake of thick patches of Caulerpa. With everything looking great to casual observation, I went to bed and woke up 6 hours later to a tank so cloudy, I could not see the back glass. I immediately supplied extra circulation, then aggressively used GAC. Tank water was immaculate in 6 hours, but decaying Caulerpa required removal by hand and vacume. On a later date, I observed telltale signs of Caulerpa Paspoides going sexual. The main stems had enlarged by 40% with white ooze coming from stems. Prior to that eminent sign, a few days earlier, the tips of fronds were white as opposed to translucent