i run Dr. G's right now......however i just so happened to be reading an article in Coral magazine from last year about a study that was done that linked activated carbon to HLLE, with Lignite carbon causing lesions within 20 days of the study, and extruded pelleted carbon only having microscopic lesions.....I know its only one study, and it was a year ago, but is this something to be legitimately concerned with running carbon?