I agree with that, i scuba dive frequently and have seen a lot of reef sharks. I have never seen a cat/bamboo/nurse shark swimming more than a few feet above the bottom. Most of the time they are laying down in caves or lounging around the rocks. As long as the tank has a large footprint, sand, and plenty of rock work/caves I see no issue keeping a reef shark in it. Provided that the keeper can provide a stable environment and quality food supplyi have multiple tanks but the tank this shark is going in and my current sharks is a 4x 2x 2x so if it were a full size it would be around 240 gallons but is technically a 120 and before you say "oh a shark should never be in a 120 gallon" it is more of a 240 than a 120 as they are reef sharks they don't really go too high up and they walk more than swim