Skimmers CPr Bak pak

[daddy01]

Hi,
I have the crp bak pack skimmer in my sump. What is the crap in the cup suppost to look like?
It says that rais/lower cup determines affluent accumulation but no reference to shich does what.
Right now mine comes out a darker color green after a few days, but the tubes are covered in green slime stuff?
Jim