I have a metal wall, metal post, metal top rim above ground pool and I was wanting to know if I need to attach a bonding lug to 4 points around the pool or just one point on the pool (possibly a post). There is not a lug spot on the pool seam. There are not bolts where the seam comes together, it is a rod that slips down over the joint to fasten the wall together. The pool is around 14 years old. I'm not sure if anyone bonded back then when the pool was built.