Activated Carbon Question

Discussion in 'General Discussions and Advice' started by Warr7207, 15 Feb 2009.

  1. Warr7207

    Warr7207

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    I understand running Activated Carbon is good for water clarity and for absorbing certain inorganic compounds.

    I would really like to know how does the Carbon clear the water ?

    Does Carbon react with every inorganic compound or does it just go after the bad ones ?

    What sort of reaction is going on between the Carbon and the water column ?
     
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  3. ziyaadb

    ziyaadb

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    good question tagging along
     
  4. Reef Maniac

    Reef Maniac MASA Contributor

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    Yup, this is a good question, and I will try to answer how I understand the process to work - just keep in mind that I'm not a chemist or activated carbon "boffin", and could be totally wrong (if so, then whoever knows better must please correct me...)

    Activated carbon works like a very fine mechanical sieve. The interior (and exterior, obviously) is full of microscopic holes and tubes/channels, and as the water passes through these channels the larger molecules become physically trapped in them - this is called adsorption (with a "d"), as opposed to absorption (with a "b") which is the chemical process of binding something to something else (such as a phosphate "sponge").

    No, it "reacts" with all molecules large enough to become trapped in the microscopic tubes/channels.

    As I understand it, the substances which cause the water to become yellow are large-chain organic molecules, and because of their size they become trapped rather quickly, and are thus removed from the water. Because the carbon does not chemically bind the trapped molecules, and they can (and do...) become dislodged quite easily, and can thus be returned to the water. This is the main reason why it is recommended to only use activated carbon for a few days and then to discard it. Also, as the channels become blocked with these large molecules the water-flow is restricted, and the carbon loses it's ability to filter rather quickly.

    Hennie
     
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  5. dallasg

    dallasg Moderator MASA Contributor

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    Thanks hennie, then the activated part?
    Yes that's why when carbon is "full" it can leech back
    Posted via Mobile Device
     
  6. Warr7207

    Warr7207 Thread Starter

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    Thanks Hennie, great explanation :)
     
  7. dallasg

    dallasg Moderator MASA Contributor

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    from wikipedia
    Activated carbon - Wikipedia, the free encyclopedia
     
  8. Warr7207

    Warr7207 Thread Starter

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    That is amazing
     
  9. TheWaterboy

    TheWaterboy Sponsor

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    yip those explanations are pretty spot on.
    just as a matter of intrest, malaysia, india and indonesia are the worls best manufacturers of activated carbon , they are cleaner with regards to carbon fines / dust and even more pourous as they made from heat activated coconut shell
     
  10. brentnorm

    brentnorm

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    Didn't realize that carbon was such a short term solution.
     
  11. TheWaterboy

    TheWaterboy Sponsor

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    it depends.......high grade carbon can be used for about 4 weeks before needing to be replaced.
    one must be carefull when buying carbon, some suppliers sell anthricite as carbon (very very low grade carbon) that can only be used for a few days before it needs to be removed
     
  12. dallasg

    dallasg Moderator MASA Contributor

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    yip very short because its so effective, i once had the pleasure of being a virology lab and they use it for air and water filtering
     
  13. jacquesb

    jacquesb Retired Moderator

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    I have also found that the "most common" and mostly "fresh water use" carbon, are made of burnt bones. This also leaches phosphates back into the water.
    Whereas the activated carbon, made from burnt coconut, does not - and these are the one's that we should prefeably be using in our marine tanks....
     
  14. brentnorm

    brentnorm

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    I only use Seachem Matrix Carbon in my tanks.
     
  15. Warr7207

    Warr7207 Thread Starter

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    Marco, I use your product, what would be an indication that the Carbon needs to be replaced ?
     
  16. Shaun

    Shaun Retired Moderator

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    The activated carbon that is made from coconut shells is the same stuff NASA uses.
     
  17. brentnorm

    brentnorm

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    NASA have fish tanks ? LOL
     
  18. Shaun

    Shaun Retired Moderator

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    Air filters etc. Activated carbon has many uses and is used for lots and lots of things, not only fish.:)
     
  19. dallasg

    dallasg Moderator MASA Contributor

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    its brilliant for air filters :)
     
  20. Warr7207

    Warr7207 Thread Starter

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    Instead of talking about air filters, any answers to the above question ?
     
  21. dallasg

    dallasg Moderator MASA Contributor

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    http://www.hallman.org/filter/gac.html
     
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