So I got Lino a Marimo Ball and a fake Bonsi. He loves the tree, sits under it or on it all the time (when he is not searching for the hidden exit he is convinced is on the side wall...). He even built his first bubble nest shortly after I gave it to him.
Also finally caught him using the cave...
I also picked up this (1/2 off clearance plus it matches his motif) but I'm not sure if I want to use it yet. It is kind of big for his tank. Of course he seem to like it from this side of the glass.
Mine mostly sleeps in his pants too.
Here is a photo of my 10 gallon. The water is a bit cloudy due to the water change recently done and I have a water bottle baffling my filter so the current wont be to strong for my betta.
And Neil, def. look around for a few more plants. The tetras need a moderately planted tank in order to live well and not be stressed. Real or fake work, and the $2 silk plants from petco work really well. I had them when I had tetras and they loved it.