The photograph is of the calcareous algae Halimeda. The algae is growing on a live rock completely covered with coralline algae. The algae should be placed in an area of very good water flow & bright lighting. Constant addition of calcium, magnesium, strontium & trace elements is a must to keep this algae at its best.
Maintaining the calcium levels in the aquarium at 400 mg to 450 mg per litre (ppt) is very much a requirement for the natural growth of this algae. A very good water flow reduces the accumulation of detrius on the algae. If the algae is not attached to a rock then it is advisable to attach it to a piece of rock using any of the instant bonding adhesives such as Super glue, Acrabond, Fevikwick etc.
