It was white but the skimmer did bog down a bit when I attached the airline. The chamber thinned out and the bubble line dropped. Didn’t pair well I’m guessingWas your media white or purple when you tried it? if purple it could have been spent. I guess all it would take is a puncture in the bag and time. I guess if your skimmer couldn't pull through the media it wouldn't work either.
I was extra careful to install it in a way that I shouldnt get kinked hoses. I am concerned about condensation / water in the line clogging it so I may print-out a drip-trap.