Hi Gerald, not so...virtually all of the mini-labs, etc, replenish, without much technical expertise. All that's needed is a spec for how much to use for a given amount of processed material, with periodic checks, such as process control strips and maybe specific gravity checks. The specified pH adjustments you mention are a bit tricker, but still at a techician level.
Originally Posted by Gerald C Koch
It mainly gets tricky when one desires to REGENERATE chemicals. That is when the chemical analysis and knowledge of formulas, etc., becomes necessary. My experience is largely in working with such operations having a staff chemist. (Obviously there has to be enough processing volume to be worthwhile.)