Ok. I don't know how else to describe this stuff floating in my tank so I'm just gonna cut right to it. I have this white substance floating in my tank and a few spots on my sand and rock. When looking at it in the tank it looks bright white but that could be the lights I guess because when I scooped it out and wiped it on a piece of tissue to look at it, it looked like bird poop. It was a brownish, green color on the white tissue. I have no clue what it could be so I'm hoping someone here might be able to help me. Thanks in advance.

