msdear thanks for reading and commenting, I am encouraging people to build one and I would say that zeolites may well help due to their ionic exchange values. I am no expert and this is all very new to me. In terms of precious metals gold and silver definitely have high conductivity but then there is the cost to that. I have found a very basic level of composition works, i found quartz off the beach and the children and i went for a walk with hammers to find them. When they were set in resin and been crushed they worked a treat in the chembuster in the garden. The tower busters i use are just auminium, or steel wool with crystals thrown in and set in muffin tins, those have really worked well. Please go the next step and make one it can only help.