The reason I ask is that I always give my used soil to my wife for the house plants. The other day she was transplanting with some of my soil and noticed the runoff water was brown. Looked like coffee. I've never seen this with my plants, but then I don't water that much and get very little runoff. The only thing I can think of is a build up of molasses. Nothing else I use is that dark brown color. I use molasses with just about every watering. Could I be using too much? If so, is that a bad thing?