Do You Have a Grainfather Conical Fermenter?

[Binkie Huckaback]

Hi. If you do have a Grainfather conical fermenter, could you do me a favour and have a squint down the inside of the liquid intake pipe ? Mine appears to have a brown stain about a third of the way down the inside. I'm not convinced and it could easily be a trick of the light, but can't be sure as I only looked properly by chance after a couple of brews. I've also posted this on the Cleaning, Sanitation and Sterilisation board without thinking to post here first, do mods, if this is not allowed, please let me know.

Here are a couple of photos: