I've had this digi for several weeks now, but after a week of it being closed up for awhile, although the polyps have been fully extended again for 2 weeks or so, it seems some brown algae grew on the ends during that time. It seems like it's bothering the coral a bit, and figured I need to find a way to get it off. Is there a way to do it where I can keep it in the tank? It was a bit of a nightmare to glue down. I was anxious to use a tooth brush not knowing if the bristles would be too tough on it / the adjacent polyps and also wasn't sure if they were treated with anything that could be damaging to the water (like some dish sponges are). Anyone have any tips for getting this off the coral without causing any damage?