This is quite possibility a stupid question... please bear with me. Is it possible to mix the developer the night before? (My evenings are quite short and would like to do some preparation work the night before. I was wondering if mixing the chemicals and storing them in a dark place. Will that be alright? ) To prevent oxizdation, can I cover it with suran wrap (I use a clear jug to mix a litre of chemicals; which is enough for one round of negatives) Will similar principles apply to fixer and stop bath?