I've decided to try developing my own film. I replaced my failing Mamiya 645 J with a less worn 1000s so I'm ready to go with 120 Kodak Tri x. I bought a dark bag and an Adorama Universal tank which comes with reels set to accept 35. Instructions don't include a diagram on 120 adaptation. They basically say 'adapt the reel to 120' and then leave me in the dark. Sorry.