I'm on board with the tank size for sure. I tried to keep a very small Foxface in my 45 until he got big enough to go in my main tank. All he did was freak out (the mottled black look

) the whole time he was in there. After 3 days I was worried that I might lose him so I put him in the big tank.
After ten minutes he was swimming around like he owned the place. A 70 might not be big enough unless you could get one built that was long and narrow. And then you would have to start worrying about gas exchange with a smaller surface area.
Just my two cents
