@cascade I think it will be a bit small to put in a 'river bank' I am planning my next enclosure once they out grow this one ,and will add one .
@Neitzchie yea sorry ,I am working on it ,just having problems uploading pics

Don't mean a massive wall, just something small that you can attached to the glass and just slop the the substrate up against it.

I mean something like this.
Made this real fast as an example.