I have 6 redline snakeheads maybe about 6" and have 2 possible tanks for them to live in next. ones a 72"long x12"wide x18"tall and the others 48"x18"x18". I cant decide which would be the better tank for them to live in before they go into a pond. Do they typically like lots of room to swim back and frth or do they like more room to turn around easier? Plz help me out, info always appreciated.