Thanks guys.
It has no bottom trim. I,m guessing the black band you're looking at is the black silicone.
I have always done as suggested with my tanks over the years. Used foam under a custom made full glass bottom and none under a framed tank, like my 90g AGA.
So I would have used it in this situation but it just does not look good unless framed. Perhaps I could find some black foam. I,m in agreement with those that sya it small size should make it fine but perhaps thats just hoping it will be.
Its half full for leak testing at the moment and ok.