I have a 25 inch space under my 29 gallons and was thinking it is good for a 15 gallons, so planning on that in the next couple months.
I go back and forth on have a shell dweller tank (I have LOTS of snails shells), a dwarf puffer tank, or put a divider and have two bettas.
I am excited with the perspective of having a multi tank, leaving in the shells and maybe having fry from it as we can leave the fry with the parents. I love my Betta and one more would be good too. I love the way puffer acts and find them beautiful in captivating...

Ultimately, I would like to try something specific with a theme, any insights for me ?