My son just put in a pool, but not just a ordinary pool. It's make from a shipping container . It's all Insulated , it is more like a big hot tub. They to first put a concrete slap down, with rebar in concrete. This tub sits in the ground level with the yard. The container is metal but has a blow on insulation , much like what they have for truck beds. I told him to put equipotential bond around this tub, but does he have to attach to the four sides of this tub? I think this tub/pool should be bonded more like a hot tub then a pool. Should he be using requirements found in Part IV . Article 680.43 ( D ).