I've been battling what I thought was diatoms in my goldfish tank for awhile. Here's a picture of what it looks like:
Then all of a sudden I had this pop up in a newly set up 5 gallon:
I thought the first one fit the description of diatoms, but now I'm wondering if I was wrong all along and the second picture is actually diatoms. Is the first really green spot algae? It just looks so brown to me. I looked up pictures of green spot algae and it just looks so much more green. Can it vary in colors?