Nov 5, 2013 #1 Azul17 Aquarium Advice Activist Joined Dec 20, 2011 Messages 180 I noticed it about a week ago and it doesn't go away. Does anyone know what could it be? Attachments image-1996458871.jpg 163.6 KB · Views: 69 image-302237048.jpg 149.1 KB · Views: 71 image-1604033143.jpg 141.6 KB · Views: 71 image-770312542.jpg 147.9 KB · Views: 72