a few months. Its a softie....so rather quickly. SPS you can literally watch grow....sounds weird but you can see the white tips...softies are quick growers with the right care. You can probably grow out a few new heads a week. Ricordea grows rather quick as well as xenia. I have been thinking about starting a xenia scrubber and then selling the xenia as it overgrows. But my mangroves are pretty freakin sweet.....so they arent going anywhere. Give them time and some good ole care. they will grow......but not overnight.