You can mix TMax liqued developer 4:1 into a gallon jug. Although it is good for up to 50 rolls, the development time changes after 17 rolls. You may just want to throw it out after 17 rolls, or after 17 rolls add 1 minute, and toss it after 30 rolls. That's at least some re-use. Yes there is a slight variation, but you still get good printable negs.(posted 8369 days ago)