Biological filter media..Whats the best out there?...
- Thread starter el wadd
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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.
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.
If we're talking about nitrogen fixing bacteria, no particles need be trapped, simply oxygen, ammonia, co2, and trace elements - all of which are in solution - need flow around them. This is because nitrifying bacteria are autotrophs like plants but they use chemosynthesis rather than photosynthesis to power the production of complex organic molecules from simple molecules of inorganic carbon and other elements.
denitrifying bacteria, which are often found deeper in the pores of the media and in the low oxygen regions of the biofilm, however, use no2 and no3 to oxidize organic compounds in the absence of oxygen. They can metabolize dissolved organic carbon so though they are not autotrophs, they don't need particles.
denitrifying bacteria, which are often found deeper in the pores of the media and in the low oxygen regions of the biofilm, however, use no2 and no3 to oxidize organic compounds in the absence of oxygen. They can metabolize dissolved organic carbon so though they are not autotrophs, they don't need particles.
True to a point but all the more reason why large dimensional surface area filter design with respect to filter size is best. Take for example the Magnum 350 canister filter with size of only 12HX5D round with a filter foot print of 18x5"= 90 SI, yet out performs the same comparable size stack media type filter (6x5=30 SI) by 2 to 1 in all areas. So its not just the media used but its surface area exposure to flow as proven time after time in industry. Only in the home aquarium market are stack filter design's used, and only for convenience and styling at the expense of effectiveness, IMVRO. 
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The 350 out preforms what comparable filters and what are we talking about here bio or mech?True to a point but all the more reason why large dimensional surface area filter design with respect to filter size is best. Take for example the Magnum 350 canister filter with size of only 12HX5D round with a filter foot print of 18x5"= 90 SI, yet out performs the same comparable size stack media type filter (6x5=30 SI) by 2 to 1 in all areas. So its not just the media used but its surface area exposure to flow as proven time after time in industry. Only in the home aquarium market are stack filter design's used, and only for convenience and styling at the expense of effectiveness, IMVRO.
Please explain because when I had the 350 I used it for mech only, it did little for bio filtration.
All I can tell you is that my Magnum 350 only had the standard 5x18 blue blanket sock and canister full of carbon. This same filter established on a stocked 60 gallon tank was used to cycle a new 120 stocked tank and it cycled it in 2 days. For me that little demonstration was proof positive that the Magnum 350 is a bio-mechanical-chemical powerhouse filter by comparison due to design.
