A replenished developer works best if you are processing film on a regular basis. If your developing is sporatic then a one-shot developer might be best such as Kodak HC-110. The concentrate keeps for a long, long time. It's also quite cheap when you figure how many rolls you can do with a single bottle ai 1+31 and higher dilutions. Look at the following website for information on this developer. www.covingtoninnovations.com/hc110