Size Approximately: 2 inches fully opened - WYSIWYG
Hammer corals are easy to keep and do best with moderate levels of mostly blue LED lighting. They require gentle water flow to cause slight swaying of their tentacles. Stronger direct flow will damage their delicate tissue. Their tentacles extend many inches beyond their honeycomb type hard calcified skeleton. Hammers are aggressive and extend sweeper tentacles that will sting nearby corals. To prevent damage to other hard corals give Hammer corals several inches of space. Direct feeding is not necessary, but they will grab and eat any food that contacts their tentacles. Their tentacles retract at night.