Substrate or Bare on large tank?

[wheelsmith]

well the important question seams to have been missed, what do you intend to keep?
rays/loaches/eels need to hide, nest builders need sustrate to shift around, veg/micro eaters need lots of surfaces to grind over rocks/pebbles/wood and some fish need surfaces to blend/camo with or non reflecting.

 

[packer43064]

Pool Filter Sand.

 

[GhostShrimpMan]

SAND

 

[bigblue22]

you could get tons of lava rock and use that