I have a white bubble coral that recently started to change to a brownish purple color. This started about a month ago, it appeared to be fine and now all of a sudden it seems to not be opening as much. I have also notice that there is some algea growing on two of the boney pieces and I know that is not good but I am pretty new at salt water and I am not sure what I need to do. I really like my bubbles and I hope I am not going to lose them.