OK what I have to say is controversial and downright heresy. (I might get shot.) But it works and I have been doing this for over a decade.
First, I freely use either C-41 Flexicolor Developer or RA4 Developer/Replenisher RT (roller transport). These developers are available from PDISUPPLY.COM in Rochester, NY in, I think, as little as 10 liter sizes.
Basically, you can mix (as per Kodak) all at once, or partial only. Then, for working solution, I dilute THAT 1 + 9 (yes, amazing) and add 5g of sodium carbonate (washing soda) per liter of working solution developer. I develop C-41 type films for from 7 to 9 minutes at 100 F. (The fastest films DO require the longer times (ie, ISO 800). I store the dev in soda bottles (the clear plastic ones) and use glass marbles to take up slack. The dev MUST be stored UP TO THE RIM or it will oxidize. It lasts forever this way. Maker certain that the concentrates are also stored 'up to the rim' using glass marbles for slack. Soda or juice bottles (the clear, brittle kind) but one thing that is very important to mention here is that PART C of the RA4 CANNOT be stored in anything other than glass or the original container. This PART C from the RA4 (NOT PART C from the C-41) does not have to be air tight for storage as it is only extremely alkaline accelerator and will eat into the sides of the soda bottles!!!
Use a normal stop bath, 100 F, but dilute so that you have about 1% glacial acetic acid.
Then, I fix in normal film fixer, also at 100F, for about 5 minutes. Then I bleach (1g potassium ferricyanide per 100 ml water) for about 4 minutes, again 100 F. Then briefly fix in the same fixer for about one minute. Then wash and dry.
You might have to slightly modify the times for development. See what you get and be happy with the results.
Color paper uses the same dilution and addition of sodium carbonate, but you MUST use the RA4 with paper and NOT the C-41 dev. Develop for at least 2 full minutes with frequent agitation. If you want less dev time, dilute less. Stop, Fix, Bleach as per film but for a lot less time. The paper process is all at 80F (ambient). I use trays for ease.
NDP2010 there is much more I could say about this but I do not want to type for the entire day. Call me at 215.569.4949 if you have problems. I will walk you though the procedure on the phone. -David Lyga