Distributing the weight throughout the system will make it more comfortable to wear. I would consider the advice about using a weighted single tank adapter to place weight evenly along your back and then place weight in pouches that fit on the cam bands. Then, place some weight in ditchable weight pouches on the waist band of your harness. The idea is to have enough ditchable weight that you can jettison in an emergency within reach that will establish positive buoyancy in recreational diving while reserving enough on the rig that will provide even distribution for better trim, pitch, roll and yaw.