yea ive got a bamboo shark in mine and i have half the back wall with rock, but make sure you have atleast 2 ft of open sand for the shark, well i guess it matters what kind of shark, if its a cat shark like a bamboo (6-12 inches long), ATLEAST a foot long and a 1ft in width for it and that also goes for a equalette the same length.
but i must stress that reef sharks grow fast, bamboos grow atleast 8 inches a year, equalette 6 inches a year. so be prepared to have a bigger tank for him, they require 180 gallons to grow there maximum( 41 inches long or 90cm)
Jake