Sounds like cyanobacteria. In a nano it is hard to achieve the proper turnover rate in order to keep dissolved organics suspended in the water column. Also, it is hard to find a skimmer that works on a Nano. Perhaps frequent water changes will work for you.
Good Luck.
:beer:
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.