I'm brand spanking new to darkroom work. I have acquired the requisite chemicals. I have Ilford Multigrade paper developer (liquid) Kodak professional stop bath (liquid) and Kodak professional fixer (powder) I have some basic questions: 1. Does the mixing of the chemicals need to be done in the dark? 2. For the developer the container says "to make 5 liters (1+9)". Does that mean 1 part liquid from the bottle to 9 parts water? 3. My tap water is relatively high in iron content. Will that affect developing? Thank you in advance for the help.