Freshwater Algae ID?
Hi Crew, What the heck are these things? Since the photo is somewhat un-focused, let me explain what you are looking at. They are 3/16″ green cylindrical, growths on the glass directly under the sides of the light. They are built with concentric rings and refract the light in a bow-tie fashion like a CD ROM (you can see the refraction in the photo and if you move your head the “bow-tie” shaped reflection rotates around the growth. I looked at them with a magnifying glass and can see nothing in the middle. Also, my pleco’s are not eating them, but keep the rest of the tank spotless. The tank is a fresh-water, South American biotype, and water conditions are close to perfect. There are no live plants in the tank because the silver dollars eat them upon entry. Thanks, Scott
