This is the algae I have been beating back & forth from the fuge to my main tank....for years.
https://www.marineland.com/seascope/ss2003_issue3.pdf
It started in the fuge, and it eventually takes hold in my main tank. The only thing that ever successfully removed it from the main was a onespot foxface. Might be time to get another, because this week I noticed it is back.
