Smart Astro Liquid

[Marcus]

Hi! I was wondering what the fluid was inside the Mathmos smart astro bottles? I've just bought one from Ebay (hasn't arrived yet) but its cloudy. 

I noticed that some people had tried a metallic bottle on the smart astro base so is it maybe propylene glycol or is it more like the standard bottles? 

I thought if it was propylene glycol I could just change the fluid as I did with my glitterball (worked brilliantly) or if normal fluid, buy a new bottle and swap liquids.

Any advice would be gratefully received!