Changing the Activated Carbon

Discussion in 'More Freshwater Aquarium Topics' started by AspiringAquarist, Mar 26, 2010.

  1. AspiringAquarist

    AspiringAquaristValued MemberMember

    I installed a new Aqua Clear 50 filter on February 19, and the carbon has reached it's 1 month replacement date. I did not use the carbon for about 7 days since I was dosing medications.
    However, I'm in the process of cycling with fish and my tank still has ammonia in it, so I'm not sure if I should change the carbon or not...

    Should I change the carbon even though my tank is still cycling? Thanks :)
  2. thequietman44

    thequietman44Valued MemberMember

    It's generally a good idea to change the carbon every month. I've read that carbon comes in different qualities and forms, and that higher quality carbon can last up to 3 months, but it's usually safer to assume the carbon is low quality and go with 1 month.

    The main task accomplished during the cycling of your tank is culturing the bacteria colonies that process ammonia and nitrite. Most of that bacteria is going to live in the filter floss and substrate, so changing the carbon shouldn't significantly affect the growing bacteria colonies.

    I've heard many aquarists say that carbon will leach chemicals back into the water if left too long, but chemistry says activated carbon cannot release any molecule once it has bonded to it without some sort of re-activation process. My guess is it's just not a good idea to leave powerful chemical sponges (carbon) filled with absorbed toxic chemicals in a tank for too long. I would think the organic chemicals would begin to decompose naturally, releasing additional ammonia etc. into the water.

    Someone else who is more of a chemist than I can probably comment on that.
    Last edited: Mar 26, 2010
  3. OP

    AspiringAquaristValued MemberMember

    Any more comments? :;scuba
  4. Butterfly

    ButterflyModeratorModerator Member

    Using carbon is a personal choice many experienced hobbyist don't but a few do. BUT since this is a cycling tank and it has fish I wouldn't change anything until the cycle is done. Beneficial bacteria will colonize on the carbon too and removing it right now might affect your cycle. If you still have ammonia removing the carbon would remove beneficial bacteria and possible allow your ammonia to rise.
  5. Aquarist

    AquaristFishlore LegendMember

    My two cents on activated carbon: I'm a firm believer that every freshwater aquarium should use it. Granted it is a personal choice and many members only use it at certain times, if they use it all. I respect that and it's their decision.

    I use it around the clock in all of my tanks, changing it out every 3 weeks. After 3 to 4 weeks activated carbon begins to lose its effectiveness. I don't feel that carbon masks any problems but removes them as long as you change it out periodically. It absorbs minerals and organic substances, helps to keep your water clear, eliminates foul odors. It will also remove medications and discoloration in the water (caused by driftwood for an example). If you're running more than 1 filter on a tank, the carbon does not have to go into every filter only 1.

    I agree with Carol. I wouldn't change out anything while you're tank is cycling. If your tank is beginning to smell foul then I would suggest adding more carbon instead of removing what is in there now.

  6. OP

    AspiringAquaristValued MemberMember

    Okay thanks. It's not beginning to smell foul yet so I'll just leave the whole tank alone for now.
  7. Nutter

    NutterFishlore VIPMember

    As stated carbon is a personal choice. I for one don't use it other than to remove medications. As Ken pointed out carbon absorbs organic substances, that includes ammonia. Definitley don't replace the carbon as not only will you remove any bacteria that are establishing on it, when you put new carbon in, it will absorb some of the ammonia depriving the bacteria of it.