Activated Carbon

  1. Jaysee Fishlore Legend Member

    I met my cousin's boyfriend tonight and he just happens to be a chemist, so I asked him some questions about activated carbon.

    Does carbon leach things back into the water?
    Yes. When the receptor sites fill up, things with a stronger affinity for the carbon will knock out things with a weaker affinity. High affinity things will remain locked up in the carbon indefinitely.

    Is what is leached any different than what is adsorbed?
    No, there is no real chemical reaction that takes place, so what is forced out is exactly the same as what was adsorbed.

    Can carbon spontaneously dump all that it has adsorbed?
    Yes, if heated to 700 C in an oxygen free environment. So under normal conditions? Absolutely not.

    How long is it effective for?
    It's not a matter of time. The carbon has a certain amount of receptor sites, so how long it takes to fill up is a function of the concentration and the rate of introduction of the impurities.
  2. backflipfronflip Well Known Member Member

    Good info there Jaysee.!!
  3. Aquarist Fishlore Legend Member

    Thank you JaySee! :)

    :animal0068:I have moved your thread from General Discussion to More Freshwater Aquarium Topics.

  4. James95 Well Known Member Member

    Thanks for reinforcing these facts for us. I will definitely bookmark this thread :)
  5. Lucy Moderator Moderator Member

    That's very interesting info Jaysee. Thanks!
    Doesn't carbon effectiveness also relate to the quality of carbon used?
  6. Akari_32 Fishlore Legend Member

    That's something I'd like to know!
  7. Wendy Lubianetsky Well Known Member Member

    That is very interesting.
  8. Aquarist Fishlore Legend Member

    ... Heat-activated bituminous coal-based granules are specially sized and far more efficient than coconut, wood, or peat-based carbons...from the link above.

    Lucy, to answer your question, I say yes. There are Activated Carbons that are better than others.


  9. raptorsvt79 Well Known Member Member

    so the bottom line would be: to replace your carbon every so often if you use it in the first place?
  10. Jaysee Fishlore Legend Member

    Yes, there are different qualities of carbon as well as different methods of activating the carbon.

    I think the bottom line is that how often you need to replace it is most dependent on water changes. If you do large, frequent water changes then you will have to change the carbon out much faster. If you never change the water, then you rarely have to change the carbon.
  11. Aquarist Fishlore Legend Member


    Water changes are a must. Nothing beats fresh water for your fish :)

  12. Akari_32 Fishlore Legend Member

    But... You'd think it would be the other way around, because water changes take out the bad stuff. So then, it should, in theory, make the carbon last longer... Hmmm...
  13. Jaysee Fishlore Legend Member

    Not all "bad" stuff is the same :) Water changes remove different things than the carbon does.
  14. Akari_32 Fishlore Legend Member

    No, I know. But, you do get what I'm saying, though, right? I just think its strange. Kind of... counter productive, if you will lol
  15. Jaysee Fishlore Legend Member

    I don't. It's not at all counter productive. Lets use chlorine as an example. Carbon adsorbs chlorine. As the chlorine molecule comes to the carbon, it gets adsorbed. Once all the chlorine is adsorbed, it doesn't continue to adsorb more chlorine because there is none. It WON'T adsorb more until more is added to the system, i.e the next water change.