I have been printing colour for about two years. I started by visiting the only (sort of) pro lab here in thunder Bay. The owner was willing to sell me some of the chems he was using for RA4 in his minilab machines, so I bought a bottle of LORR Developer/Replenisher and a bottle of LORR Blix. These are the chems that Kodak recommends for minilabs that have a good turnover, so I expected that the chems would oxidise quickly and have a resultant short shelf life. Nothing could be further from the truth. I bought a bunch of 250ml brown glass bottles from a guy on ebay. I think I got 84 of them for $20 plus shipping (another $30). I decant the concentrate into the smaller bottles so there is as little air space as possible to keep oxidization to a minimum. To make this long story somewhat shorter, the chems last really well in the small bottles. The original developer I bought two years ago is still the same light amber colour it was when I decanted it. When I open a fresh bottle, it gets pretty dark (about like rodinal!) by the time I have used up the small bottle, but it still works the same as the fresh stuff. In further web-based research, Kodak says that the efficacy of the developer does not seem to change as the colour darkens (up to a point I suppose). I decant the blix into the same bottles for shelf storage. The LORR blix is a single solution blix that is mixed with equal parts of water as a working solution. A 250 ml bottle mixed gives me 500ml of working solution. I get around 30 8X10 prints before the blix exhausts, so I throw the solution away after 25 prints. So the 5 litre bottle of blix will process 500 8X10 prints.
I work at room temp (around 72F). I had to play around with the dilutions for the developer to work at room temp.
My work flow is pretty standard for RA4 processing (rotary):
30 sec stop (I use indicator stop bath)
30 sec wash
2 min blix
I found a carton of 4 bottles of LORR developer/replenisher(1.3 litres each) on ebay for 9.95, and that's what I won it for! The bottles don't have any expiry dates on them, and the chems in them are significantly darker than the new bottle I have (they are probably several years old). Anyway, the older chems work exactly the same as the new chems, so I decanted them into smaller bottles, and I'm using the old chems since I figure the new stuff will have a longer shelf life.
Mixing is stupid easy. My drum uses 50ml of solution for developer, so I mix up 500 ml of developer to process 10 prints. I fill a one-litre graduated cylinder to 500 ml and use a syringe to measure 16ml of the concentrate. This gives me the correct dilution to make a processing time of 2 minutes.