I wasn't saying that you made a mistake nor that the results are wrong. I was just curious as to what are the different ways to illustrate test results. Different test kits have different indicies. I know for a fact that the dying/decaying tissue is toxic (obviously) but I never knew that a skeleton could be toxic. ::-/ Dang, all my tanks must be a toxic, flourishing dump because all of my base rock is dead coral skeletons.