I was looking into getting this kit. I read the pdf and one thing is sort of catching me off guard. If you buy the 1 pint kit it gives you a total of 472ml of liquid to work with at each stage. I use a patterson universal tank and I usually develop with 600ml of liquid. I believe the minimum is 500ml. I shoot 120 film. Does anyone in here use the kit for 120mm film? If so how do you deal with the above? And lastly I know that once the chemical is mixed it has a short shelf life. If I were to buy the gallon kit and mix a little at a time how long would the unmixed chemical last on the shelf?