Hi Rob, Welcome to Oozing Goo The Lava Lamp Syndicate.
I hope you get a good answer regarding your Green Fluidium. There are some real experts here, especially my mates Astrobaby and Bohdan. I too own one and in green too! (my first of 4 flueys). I've kind of neglected mine though (have not run it for about 4 years) in favour of many other lamps I have purchased since then. I think I'll need to check it out to make sure it hasn't gone the same way as yours.