Algae driving me crazy!

[Rusty Dalton]

Can someone identify this algae and how to control it? Large CUC not handling it.

 

[Hermie]

cyano bacteria or dinoflagelates, someone else may be able to indicate which, or a cheap microscope could give you a better idea

clean up crew doesn't eat that

 

[Jekyl]

CuC will never take care of it completely. Just manage it. How old is the tank? Parameters? Use a toothbrush on the end of your siphon during water changes and scrub/suck it out.