My ICP test on RODI is all 0 but Tin is 0.54 ug/l. Is that likely? What would be wrong with my RODI unit only allowing Tin through. My tank reads Tin at 32.30 ug/l and ICP test suggest 3, 20% water changes. I agree with the water changes but I am skeptical of the RODI unit allowing only Tin to pass through. New DI resin, RO 1 year old and TDS reads 0. What do you think?