funny story, I got a building an obsession camera tube to try to up my top down pic game. well my nano 25g is honestly too small for in tank housing lol. when I stick my camera in with it, it takes up like half of the usable spaceI have been using my Sony A7III with a 30mm f1.2 manual lens (aps-c lens not full frame). I have an underwater housing for it as well for when I release trout when I am fishing and used it a few times to dip into my tank. It is kind of a chore since it is quite bulky. Here is a pic of my Tyree pinky the bear.
edit: excited to finally setup the 60g, maybe then the camera tube will be of some use.