Caulerpa is a macro algae which is beneficial to reef systems as it consumes phosphates and nitrates while producing oxygen. It is best kept in a refugium, but it comes at a price and is not recommended as a method of macroalgae filtration.
Caulerpa reproduces in two ways, by fragmentation where pieces break off and take root elsewhere and by going sexual. When this happens it is normally on a large scale and it has the potential to crash your system. Stems become loaded with reproductive cells in liquid form. The stems eventually burst to spill the liquid into your system and leaving behind a deflated translucent mess to decay and die. Water yellowing will precede the event so caution is advised.
Manual removal of rocks from the system and brush cleaning is the safest and most effective method of removal.
Spot treatment with hydrogen peroxide also proves effective.