Some types grow tall and some grow as mats. Growth of all Caulerpas develops along a main runner from which leaves grow along its top and roots along its bottom. Caulerpa roots are used solely to anchor the plant in postion. Caulerpa fronds are filled with fluid and are very thin-walled. It is important to acclimate them slowly to a new environment, especially relative to the salinity of your water.
Rapid changes can rupture the cell walls and cause the plant to die.
Marine algae should be handled delicately as it is quite brittle and cannot support its own weight out of water. Caulerpa that is already attached to a rock gives the plant its best start in your aquarium. Feather Caulerpa grows much more quickly than does the 'Grape' variety. Light pruning should be performed frequently once the plant is established. This is preferable to infrequent, heavy pruning.