Thank you. As usual there were many good entries. I am pleased to get an algae into the winners circle along with the fantastic coral entries.
The shot is a bit different because it is backlit with sunlight. The bubbles are oxygen from midday saturation. I had a tank that I kept in a south facing window. Even in the dim Chicago metro area I was able to grow acropora. The tank was good for pictures, but overall was rather boring, with predominately browns and yellows. I was never able to convince anyone else to set up a natural light tank.
The photo was taken with a Nikkor 105mm macro lens.