orange/ brown sludge in cistern of toilet

[darckins]

Hoping someone out there might be able to help me, I recently had to lift the cistern lid to fix the flusher and noticed all this orange/brown sludge along the internal walls and bottom of my cistern, also all the tiles in my showers are covered in an orangey/ red film of gunk that is next to impossible to remove.
I had a look at the tanks in the attic and the cold water tank is full of this same sludge, is this dangerous and is there anything that I can do about it as I am drinking this water .

thanks in advance for any help.

 

[Armo74]

If by drinking it you mean brushing your teeth in it then you could change your cold basin tap feed so its fed from the mains if the taps are seperate.

 

[Corgigrouch]

Just a bit of rust from the iron pipes out in the road.... Don't worry about it.