 In a shark aquarium setup (preferably an oval-shaped tank for more active species), there should be much surface area (wide and long tanks with good gas exchange/more room for biological filtration and room for sharks to swim, glide, and turn with little constraint opposed to tall, thin tanks), fine substrate (coarse substrate can irritate the shark's underside), little décor and rockwork (which should be secure) for swimming space (sharks in the orders Orectolobiformes and Heterodontiformes however, feel more secure in tanks with caves and ledges), excellent filtration (sharks are messy eaters and need good water conditions), protected heaters, filter intakes, etc.by surrounding them in polyurethane foam barriers (unprotected equipment can be dangerous to active sharks), and a secure canopy (sharks can jump out of the water) as well as, strong, steady, linear water flow (10+ x the volume of the aquarium per hour) moving in a gyre circling the aquarium, dissolved oxygen levels of 7-8ppm (slightly more if you are using ozone), low light levels, and no stray electrical currents/amounts of metal in the aquarium water.Many sharks feed on invertebrates to a great degree along with fish (even ones that are larger than themselves), and although they don't eat coral, they can knock them over and rest on them.