questions on chaeto and RODI

[e46er]

its not the furnace door its the mechanical room door and its not the doors as when i touch them to open them to shut off the rodi unit im groundedand no shock and its the plastic tube from the rodi unit. my sparky friend is stumped as plastic doesnt conduct and RODI water doesnt conduct. its how tds meters measure more conductitivity higher tds. well we will get a meter and get to the bottom of it ill let you guys know the outcome