This is about as good of an example of dark green slime that you can get. This HOG3 or 3x or 3xx is pull out of a saltwater sump, with probably very high nutrients, which is what causes dark green slime. More http://algaescrubber.net/forums/show...he-best-filter

Click image for larger version

Name:	UasThomasDuncanFW-7.jpg
Views:	23
Size:	87.7 KB
ID:	8466