Well it has been a few weeks and I think I figured out my problem with my Zebra Eel. When I got my master test kit, it was missing a very important test, NITRATES! I bought a test kit for nitrates and what do ya know, off the chart. Mixed up a 40% batch of fresh saltwater with my new ro/di system, waited 3 days and did a 25% change and I am glad to report that the thing on my eel is gone and living organisms are thriving on my live rock again. I am trying to get them as low as possible, at 10-15 right now. Unleashed, I would like to say THANK YOU again for your help.