Isn't this thread suppose to ask about coralline algae? I don't know. Every thread that you post seems to take other directions. Or is it just me? Now were back and forth with sps care. Search this forum and google for the algae question. You will find your answer there. If you are concerned about flow, start another thread title. If you are concerned about sps care, start another thread title. As well, please use capitailization. It is difficult to read if you do not use correct grammar.