Steven Lee
Member
Having said that, XTOL-R can be a very stable developer with a clear economic advantage of only 70 ml per roll of a 35mm film. It does require slightly more discipline and has a bit of a learning curve. Is it worth it? To me, it is, at least for now.
I am torn. On one hand, I enjoy not having to mix chemicals for months. A single 5L batch of Xtol-R lasts me a long time. On the other hand, I am a bit annoyed by the need to monitor activity. Simply adding 70ml after each roll does not work: the activity will be drifting, especially if you develop sporadically and use many different films. Developing 10 rolls of HP5+ in a row will not produce the same amount of byproduct as developing 10 rolls of Delta 100, that's why I purchased a densitometer and adopted a habit of adding a control strip to every batch if there's room in the tank.
In old threads people reported that activity also gradually drops during storage. I have not personally verified that, but this doesn't sound improbable.