Whoa! Vibrant put some of that in my tank also. I believe it's a type of spirulina. It was around the top edge of my water on the glass and I scraped it with a razor blade in my fish went crazy and ate it as it was scraping it. However they wouldn't touch it until I did that. I no longer have any in the DT but I discovered some in my sump all at the water line. Take a look around and see if you can find a thread about getting rid of spirulina. That might be of more help. I haven't had time to do that myself yet.



