I've seen healthy bamboo sharks in 300-400 gallon tanks. The trick is having all dimensions at least a foot longer than the maximum size of the shark.
I have an Idea:
How about very little LR in
the aquarium, instead have like a five inch DSB
with sand sifters. In the sump should be like 200-300 lbs of LR
, to make up for the rest of the biological filtration. This ensures the shark has plenty of swimming room.