I do run GFO, same GFO I run in my other system with no issue. The orange film is slimy like algea, it's not dust like, that's why I'm thinking it's algea.Do you run any type of GFO?
The few times I’ve seen this it usually ends up being the dust of rowaphos or the likes
Yea filter socks looks dirty but they been there for only 2 days, that orange coloration occur almost immediately after the replacement. Does GFO remove silicate?looks like the normal algae film to me. don’t know the name. i always just wipe it off. running a phosphate/silicate removal media will slow it down considerably. the filter socks are dirty, need to be taken out ave cleaned once a week. many ways to do it. i do washing machine with bleach and dye/perfume free detergent and air dry in the sun.