Honestly why not just buy a big tank and glue some plexiglass down the center with a large hole cut into it then you could get the same effect and not have to worry about ruining 2 tanks, weakenin the glass or cleaning problems. Just a thought. I mean you could still even put the tube in if you put in 2 dividers. thta would be really wild looking.
a very rough idea of what i had in mind

a very rough idea of what i had in mind