Oh, another thing to consider is rockwork. I used to use a bunch of tonga branches to raise larger rocks of the sandbed to allow for more swimming areas for my tangs. They would race around through the new structures like it was a racetrack. If you have enough space in your sump you can always throw your less attractive rock down in there and open up your display some.
200g-No Corals Yet!
I agree with Erik.
When I tore down my old tank I was surprised how some fish (the anthias especially) seemed to really respond well to the open space.
It was a big decision maker in the design of the new tank: less rock, more tunnels and more really open space to swim.
Karin
It's pretty open already but could use some improvements. I have a cave on one side that a lot of the fish like to hang out in. On the other side it's pretty much just open space. They spend some time in the open but the cave seems to be their favorite place.
Master Reef Curmudgeon
Depends on the fish I'm sure... my 3" tang is about .5" thick, maybe more after a good meal. But my 2.75" clown is probably .75" thick. She's big boned.
Does anyone else's fish freak out when you put a ruler up to the gl*****
Cool link Karin, doing some measuring and math now.