Especially when it comes to some marine macroalgae of the species Caulerpa you will come across the words sporulation or "going sexual", which means nothing else than that the caulerpa marine algae is dying off and starts a reproduction cycle, which than often is clearly visible as it turns the water milky cloudy, depending on the amount of caulerpa species which has died off.

The sudden die off of Caulerpa species is a known process which rarely happens, but it may be triggered by sudden/massive changes of water parameters of the water temperature, the salinity, alkalinity or ph levels.

Therefore it is important as always in this fantastic marine aquarium hobby to keep the water conditions as constant as possible and to remove any dead parts of the macroalgae as soon as possible.

Should it have been triggered we recommend a large water change of 25% and more. 

This said we keep caulerpa species since more than 16 years successfully in our macroalgae tanks without any "going sexual" event at all.

This problem won't btw not happen with most other macroalgae species, like Ochtodes, Ulva, Gracilaria etc.