I filled my tank the other day and I was looking at it and I noticed that there is something on the surface of the water. It's I would say grayish. It looks like oil but not oil. When I put my finger in the tank to try and see if anything would happen it went away but then came back as the water settled. I thought maybe it could be from the florite substrate since the water was real cloudy at first but I dunno. I'm trying to get a pic up but my phone is not working now but any ideas would be good. Thanks.