To be honest, I find it weird having a shark in a tank built for sps. I am always interested in the welfare of animals, although my input is not relevant and my opinion does not matter.
If I can spark up info to better assist another aquarist, I will. Hens, lighting and size of the tank for the next person to come along who wants to keep this same setup. I think having a shark in a tank under 200g with a nem is a bad idea... for the sharks health.
Further, if you do have a big tank, you obviously need allot of water movement. I'd be worried of the nem getting into a powerhead and polluting the tank, thus killing the shark and other inhabitants. This is assuming you have power heads and are not just relying on your sump return to turn the water.
Never had someone avoid a simple question. Just find it weird. Most are normally happy to share little info like this to help other aquarist...