Yup that activated carbon is amazing stuff. Do you know I did a test on claims that carbon increases phosphates by placing new carbon in RO with an aerator and then after 24 hours measuring differences between RO before and without free floating carbon, and then after with the carbon and difference was like no difference in the chemical test 0.
Incidentally so that im not misunderstood, I understand that at the microscopic level some materials have far more surface area (like carbon) and therefore logically be more supportive for bacteria colonization. While this is true fundamentally it is also true that the reason why they colonize these tiny high surface area crevices is because the food they need gets trapped there as well and where the food is the bacteria go, no food no bacteria. This is where media configuration for surface area exposure (format & footprint) is so important. Even in water reclamation where bacteria plays a huge role they understand that the carbon has to be spread out thin on grates for maximum mechanical exposure relative to the flow of dirty water otherwise you just don’t capture as much trapped dirt (bio food) and all that thickness of media simply gets blocked by the media in front resulting in early clogging, not more bacteria colonization. The more media that is stacked in series against a given flow footprint, the less effective that media becomes regardless of what its made of. In contrast a parallel filter even though having the same GPH, because of multiple access points and much larger surface areas will trap substantially more dirt while at the same time maintaining more flow and more OX levels to colonizing bacteria. Its like two identical skyscrapers with different methods of moving people, you can have 4000 people waiting in a line outside the parking lot for 7 hours to access one security check point and get to work, or you can every entrance open around the building with added security to check those same number of people in 20 minutes. The thinner a given amount of media is spread for exposure to a given amount of GPH the more food it will trap and bacteria colonization it will support, conversely the thicker a given mount of media is stacked against a given amount of GPH, the less food it will trap, less OX exposure, less bacteria colonization.