Originally Posted by urbguy
It really sounds like you have a "Thread Algae" problem. If you have other plants in the tank, it should out compete this strain of algae, some fishes eat them but not all.
Check out this page and see if thread algae matches what you have in your tank! Good luck!
It looks like it could be thread algae. I have a marimo ball and three types of moss will those out compete it ? I remove it when ever I see it.