Beer hydrometer for cider

I plan to brew some cider in the near future,using the  gear i bought to  brew some beer but never got round to.The hydrometer has markings for beer &wine but none for cider.Now i've had some conflicting advice on this subject ie:it wont work,or,it will work but you have to get a new set of readings for it.(?)
 Personally i'd have thought that beer &cider would be pretty much the same,but now i'm not so sure.
 Can some one please help me out?
  Cheers
 Tel.

Thanks