I'm new to reef keeping and have had my 75gal for about 3 months. I added 2 clowns and a prawn goby as well as a hammer coral over several weeks and they are all doing fine. Water is doing great too. I've noticed these little trees growing from the live rock and have no idea what they are. I can't seem to find any info on these. Does anyone know what they are and if they are good or bad?