The Biorock project in Pemuteran Bali Indonesia is the 1st and the biggest in the world. They use steal structures with electricity ( 12V) to grow the coral attached on it 4x faster than normal grow's rate. ( http://www.biorock.org/content/pemute... )

It has been in the water since 1998 and is taking care by the Biorock Center Pemuteran ( http://www.biorockbali.webs.com/ )