Maybe 10 years ago, mixed up 5 liters, 2 or 3 weeks later just gave out. At the time this seemed to be an issue, sudden death as opposed to just petering out over time. I dont recall the roll count as I was using 1:1 and dumping. I am reconsidering X trol as I am slowing using up all of my old stock and want to use a developer that I dont need mail order.