just four weeks ago I disscovered 5 small white pinhead size growths on my rocks...now I know what they are ...very small toadstool corals, they've grown to the size of a a few centermetres in hight and i can very clearly see what they ....its really exciting when you can see your tank doing what naturally happens in nature.....I don't know why or where they came from...but the growths are very close to two of my large toadstools.