I finally go around to mixing my first batch of RA4 chemistry today, with the plan to get in the darkroom this weekend. I bought the two kodak 20L dev and blix kits from here: http://www.ag-photographic.co.uk/process-ra4-117-c.asp. This is a great kit as it is split into small bottles with the idea of making 4 x 5L sets of working solution, however I only wanted to mix 2L of working solution. Unfortunately the small bottles only have basic mixing instructions - 3.75L water +part A, B & C + water to 5L. None of the bottles had individual volumes on them. I think I measured them correctly, but I'd appreciate it if anyone who has used this kit can confirm my measurements. For the developer I measured part A=250ml, part B=150ml, part C=250ml. For the BLIX I measured part A=710ml, part B=1L. Please can someone confirm these. Assuming I got these right, my next question is about using them in trays. My darkroom temperature is cold right now, probably 15 degrees C, so room temperature is very low for developing. I'm planning on using the small heater I use to maintain water temperature for C41 development. I wanted to just submerged this in the developer, do you think this will work? As I only have one heater, I was planning on using the stop and blix as room temperature. This shouldn't cause a problem should it? Thanks for your help.