Thanks for your reply. I did Andreas flush both times. The first time I had about one dozen lime green stones (very tiny). I didn't see any of those this time. I had dozens of tan mushy stones that float on top of the water. I was wondering if they are cholesterol stones? But...they are not hard at all. They almost look like tan sponges, very small about 1/4". Do you think they could have formed as a result of the oil/grapefruit juice mixture?