Well I get excellent results with the Kodak products at room temp. I use the mixing proportions on the bottles to mix up 1 or 2 liters of working solution at a time, without using starter. I process in drums and will use 75ml of working solution chems for a couple or three 4x5 test prints and an 8x10. Purge the air out of the stock bottles and the concentrates will keep a year.