Howdy folks. I had a question about soaking mazon creek nodules before starting the freezing process. I’ve had mine soaking in water for 2 days (prior to the first freeze, will be several more days), and there seems to be oil on the surface of the water. Is this normal, or is it something I should be concerned about? This is my first time doing this, and I just want to make sure I’m doing it right.    It is just plain water, I’ve added nothing else to it.      Thank you!