Kenny's Discus     LT - 090909 - 120x60 Logo     Australian Blackworms

Page 1 of 2 12 LastLast
Results 1 to 15 of 19

Thread: carbon

  1. #1
    Registered Member chompy's Avatar
    Join Date
    Mar 2006
    Location
    Halifax
    Posts
    151
    iTrader
    0

    Default carbon

    I have always been told to not use carbon because it will release toxins it has absorbed before hand. Is this true or is it anouther reason why we don't use carbon?
    Tyler

  2. #2
    Administrator pcsb23's Avatar
    Join Date
    Dec 2005
    Location
    Hampshire, UK
    Posts
    8,346
    iTrader
    3 (100%)

    Default Re: carbon

    Tyler,

    Carbon in itself is not a bad thing. There is no need to continually use carbon, particularly with the higher water change regime normally associated with keeping discus.

    Carbon is indiscriminate in what it absorbs, ie it absorbs good things as well as bad things, in soft water the trace elements that are essential to all fish will get absorbed quickly and will adversly affect the fish.

    Carbon should be used where you wish to remove meds and if you suspect a toxin has been released into the water say from an aerosol (like fly killer spray). Although both effects can be achieved with water changes.

    hth,
    Paul

    Comfortably numb.

  3. #3
    Registered Member chompy's Avatar
    Join Date
    Mar 2006
    Location
    Halifax
    Posts
    151
    iTrader
    0

    Default Re: carbon

    Thats what I thaught, but I was just told otherwise by a few people which made me second guess myself
    Tyler

  4. #4
    Registered Member mickeyG's Avatar
    Join Date
    Mar 2004
    Location
    Virginia
    Posts
    160
    iTrader
    0

    Default Re: carbon

    pcsb23 is exactly right. If you have a need for carbon like removing toxins, metals, meds, it is ok to use periodically. But like he says, once the carbon is full (all the surfaces have stuff on them), it will begin to release those back in the water.

    So you need to remove/replace the carbon before that happens.

    Michael

  5. #5
    Registered Member
    Join Date
    Jul 2005
    Location
    Chicagoland
    Posts
    2,388
    iTrader
    3 (100%)

    Default Re: carbon

    I have to somewhat disagree. Activated carbon should not release anything that it has trapped. btw it works by aDsorption not aBsorption (a sponge absorbs things, actived carbon works in an entirely different way. Particles are attracted to the micro pores in carbon and are trapped there), Having said that I do agree that it isn't needed normally. It has two things which are detrimental to an aquarist IMO
    1. For carbon to work properly water must flow SLOWLY past it. Almost none of us have flters which have a slow enough flow for carbon to be truly effective.
    2. Cost. Carbon is just cost prohibitive, it fills very quickly and is no longer useful in a very short time (far shorter than the month or so that most users keep it in their filters).

    It is excellent, as Paul already said, for removing medications. It is also useful in removing DOCs (Dissolved Organic Compounds). However, also as Paul has already stated, wc's are usually a much better solution to both of those problems.

    Larry

  6. #6
    Registered Member mickeyG's Avatar
    Join Date
    Mar 2004
    Location
    Virginia
    Posts
    160
    iTrader
    0

    Default Re: carbon

    Larry,

    I don't know that carbon leaches back for sure never having used it. My opinion is based on others. I will say that I have been reading all the techy stuff about aquariums for about 5 years and the predominant (I bet 75% or more?) of the opinions (many from the leaders in the industry & books) is that when the carbon is full - it will release some of its load back into the water.

    I can't give you the actual data how or what they base their opinions on, but I'll try and take the time to read more and then repost.

    As far as the price being prohibitive - I have to somewhat disagree. I bought 1.87L of marineland black diamond carbon on the net for $9.99. It looks like a ton. I thought I would use it in a little corner filter in my water mixing container but decided not to use it. But if I used it all the time it would last a year or more. I admit I only make 20g of water twice a week, but unless you have hundreds of gallons, it wouldn't be THAT expensive.

    Michael

  7. #7
    Registered Member
    Join Date
    Jul 2005
    Location
    Chicagoland
    Posts
    2,388
    iTrader
    3 (100%)

    Default Re: carbon

    Quote Originally Posted by mickeyG
    Larry,

    I don't know that carbon leaches back for sure never having used it. My opinion is based on others. I will say that I have been reading all the techy stuff about aquariums for about 5 years and the predominant (I bet 75% or more?) of the opinions (many from the leaders in the industry & books) is that when the carbon is full - it will release some of its load back into the water.

    I can't give you the actual data how or what they base their opinions on, but I'll try and take the time to read more and then repost.

    As far as the price being prohibitive - I have to somewhat disagree. I bought 1.87L of marineland black diamond carbon on the net for $9.99. It looks like a ton. I thought I would use it in a little corner filter in my water mixing container but decided not to use it. But if I used it all the time it would last a year or more. I admit I only make 20g of water twice a week, but unless you have hundreds of gallons, it wouldn't be THAT expensive.

    Michael
    Michael,
    This is actually precisely why I decided to address the issue. As you can tell I agree fundamentally with what Paul said. Except that carbon can not possibly leach things back into the water column. The reason is because carbon is not a sponge. It does not work that way. Carbon chemically attracts ions to itself (think of it as a magnet) there is simply no way for it to leach back things once it has them other than to reverse the ionic process, which is something that is so unlikely that it borders on the impossible. As to cost, if you read what I said, and perhaps I didn't say it well enough, for carbon to remain effective you would need to replace it every two days or so, so I stand by my orignal statement, it is cost prohibitive.

    Larry

  8. #8
    Banned
    Join Date
    Jun 2006
    Location
    Halifax Nova Scotia
    Posts
    3,198
    iTrader
    0

    Default Re: carbon

    Hi Guys this is my 1st post here and I haven't had discus in 30+ years, but Tylers orginal question was due to my disagreeing with him on our local board that AC released it pollutants back once it was exhusted/spent...full.


    I fully agree with Larry...it cannot happen. The pollutants are chemically bonded to the carbon and for them to be released it takes acids, steam or extreme heat...like 1500*F...not many things that are available in an aquarium or a pond. AC has it's place in the hobby but it's not required on a regular basis.

    Now if it's acting as mechanical media then it probably would dislodge some fines when distrubed.

    Regards Graham

  9. #9
    Registered Member
    Join Date
    Feb 2005
    Location
    Park City, UT
    Posts
    1,373
    iTrader
    5 (100%)

    Default Re: carbon

    No reactions are one way. They are always bidirectional. Sometimes one direction is greatly favored. Acids are plentiful in a Discus tank, as they are constantly made by the nitrification process, and can interact with the carbon to produce a more favorable reverse reaction, depending on how much nitric acid is in the tank, and how much of the ions have been adsorbed. Once the carbon is "full" of adsorbed ions, it is much more likely that ions will be "lost" to the tank water, than when the carbon has a deficit of organic ions.

  10. #10
    Banned
    Join Date
    Jun 2006
    Location
    Halifax Nova Scotia
    Posts
    3,198
    iTrader
    0

    Default Re: carbon

    Sorry............ I'm going to have to 100% disagree..I have a world reknown PhD in chemistry who is into ponds and koi big time...and they produce a whole lot more ammonia for the nitrification cycle than any discus ever could even in soft acid water......along with a local aquarium hobbist who happens to have his Masters in chemistry and works for the university, Along with the best chem whiz I've ever met all agreeing with me and Larry .


    The following links will give you the threads on some other boards about this topic with Dr Roddy Conrod, PhD, Dow Chemical; Roark my chem whiz (Jeff Hunan), Engineer in a number of different sciences and Happychem / Stuart McDonald a hobbyist and Masters in Chemistry here in Halifax.........

    http://www.koiphen.com/forums/showth...5&page=1&pp=10
    http://www.eastcoastaquariumsociety....ic.php?id=7211

    Also here is my question to Seachem support and their response..................

    ''........Is AC capable of de-adsorbing all it's pollutants once it
    >has reached it's adsorbing capacity or does it hold onto them
    >indefinitely as I've always been taught
    ================================================== =============================

    Your belief is correct. I'm not sure where this misconception
    originated. I do not know of any filter media that adsorbs
    pollutants to capacity and then leaches them back in. Once they have
    adsorbed all that they can your waste will rise again because you
    are lacking any open adsorbent media not because they are being
    leached out of the media.

    Best Regards,
    Seachem Tech Support~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Seachem Laboratories, Inc. www.seachem.com 888-SEACHEM
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ch

    ================================================== ========


    While I'm not a chemist, and rely on actual chemists to back up what I've come to know, having had aquariums and fish for the last 46 years and even having bred discus about 30 years ago and having used AC a lot over the years .....Please post the chemical reaction that has aquarium produced acids breaking the chemical bond with the AC.............science please.

    Other than that, the notion that AC releases toxins back into the water once they have exhusted that ability is pure myth and there are enough myths in the hobby now with out more being put forward

    Regards Graham


    Edit I see that your a Prof of Neurobiology so you should have some understanding of basic chemistry......... If they are capable of releasing/ leeching toxins back into the water what are those toxins???


    Regards Graham
    Last edited by Graham; 06-19-2006 at 10:00 PM.

  11. #11
    Registered Member mickeyG's Avatar
    Join Date
    Mar 2004
    Location
    Virginia
    Posts
    160
    iTrader
    0

    Default Re: carbon

    I am not going to post the links or info (way too long) but I have done some research the last 4 or 5 days on the subject. I have read about 20 articles many from well credentialed chemists, and I was wrong.

    Most of the experts (all but 1 that I saw) say that after gac has finished adsorbing the offenders (explained the 3 types of adsorbtion in some of the articles), they will not leach back into the water. A few said that there might be very small amounts of a few specific elements that could get into the water but that they were insignificant amounts.

    They all mentioned too that they were not sure where the common misconceptions came from, but the fact that they all mentioned this point shows how there are so many opinions from each school of thought.

    Michael

  12. #12
    Registered Member
    Join Date
    Jun 2006
    Location
    Illinois (South suburbs)
    Posts
    401
    iTrader
    1 (100%)

    Default Re: carbon

    Good information. This should be made into a sticky.

  13. #13
    Registered Member
    Join Date
    Feb 2005
    Location
    Park City, UT
    Posts
    1,373
    iTrader
    5 (100%)

    Default Re: carbon

    Actually, I do not disagree that AC will likely not leach much of anything back into tank water once it has become exhausted. At least, nothing of significance. I was only making the point that 100% adsorption is theoretically impossible.

    I actually believe the negative consequences of AC are:
    1) If you are relying on it to remove toxic substances in your tank, you never really know when it is exhausted, and once it is, those toxic substances will build up quickly in your tank

    To answer the original question:
    "or is it anouther reason why we don't use carbon?"

    2) More importantly, as Paul indicated "Carbon is indiscriminate in what it absorbs (adsorbs), ie it absorbs good things as well as bad things, in soft water the trace elements that are essential to all fish will get absorbed quickly and will adversly affect the fish." I believe this is the reason that AC should not be used in a discus tank. Soft water has little of the essential trace elements it to begin with, and AC will take out what little is left--leading to potential sickness. I believe that many of us Discus old-timers have had HITH at least once in our experience, and have had it cured by pulling out AC.

    AC does have its uses as a prefilter before RO units to remove chlorine and chloramine that can damage certain types of RO filters, and to remove other nasty compounds before or after RO units that exist in some water supplies. It is also very useful for temporary toxic compounds (such as plastics, sprays, etc.) that happen to get in your tank water, and for removing medicines, once the treatment is finished.
    Last edited by Alight; 06-20-2006 at 02:41 PM.

  14. #14
    Banned
    Join Date
    Jun 2006
    Location
    Halifax Nova Scotia
    Posts
    3,198
    iTrader
    0

    Default Re: carbon

    Sorry I must have taken what you wrote the wrong way......But it sure sounded like you thought it could release it's toxins back in....anyway.

    As to whether AC use is a good thing or not in a soft water environment, or any aquarium for that matter on a regular basis...that's a whole other discussion and personal experiences will definately play a role here. I have very rarely used AC in the 20 years or more. It has it place on the shelf as another tool when needed for cleaning up the water from whatever, but I would much prefer to do a water change...... I even have a 50 pound bag of it around here somewhere for that day when I might need it

    G

  15. #15
    Registered Member fishmama's Avatar
    Join Date
    Sep 2006
    Location
    Kansas City, MO
    Posts
    1,189
    iTrader
    0

    Default Re: carbon

    Please forgive me for my simpleton reply...I most certainly agree that it is not intended to replace WC's, but I find AC very effective and helpful. Perhaps the expectations are unreasonable thus resulting in AC being left in circulation too long.

    Is it possible that AC left in place after "useful life" may become a favorable environment for secondary growth of undesirable bacteria and/or parasites? Hence, the conclusion that "It must be the carbon."?

    Just wondering.

    Thanks

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Tiger Deal Slasher! Savings up to 70% OFF!             AquaticSuppliers2