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Carbon
- Thread starter Hirobo
- Start date
I run mine 24/7 for no more than a month before changing it out.
Hirobo said:
I do both regularly. Water changes AND add Trace Elements.
jonathan. said:
I hate people who do this, but where did you read that? Wouldn't it depend on the amount of carbon relative to the water volume being processed? If I have a 55G reef and I run that water through a 6' carbon tower, it's not going to be true, is it? Just seems like an illogical "rule" to me.
BTW, I run a comparatively small amount of carbon in a TLF reactor and try to change it monthly. The last time I slacked off and the water started to get a little yellow (der gelbstoff). That's when you REALLY know you need to change the carbon. I think Delbeek and Sprung actually recommend using that as an indicator in their first volume, though I think we've advanced a lot since then.
Jim, there are a number of studies done (though older studies) that support the theory that Carbon looses most of its absorbtion after the first 2 weeks, it still operates, but much less effective after that.
http://www.cee.vt.edu/ewr/environmental/teach/wtprimer/carbon/sketcarb.html
http://www.hallman.org/filter/gac.html
http://www.malawicichlidhomepage.com/aquainfo/activated_carbon.html
Though now with the common use of a new kind of carbon called ROX .08, which has a very very high clarity and mollasses count I belive that many are agreeing you can go longer.
Personally, I have found using generic LFS carbon and the carbon we get from the Group Buy, that the 2 week rule is correct, I have done a number of tests in my QT tank with carbon in a phosban reactor clearing a tank with Methyl blue I added.
ROX is very expensive, but really really good. You use so much less for the same tank volume, and it lasts *slightly* longer (IMHO), that it is worth the extra. (I am using 1/2 cup, every 2 1/2 weeks a water volume of 120 gallons)
http://www.cee.vt.edu/ewr/environmental/teach/wtprimer/carbon/sketcarb.html
http://www.hallman.org/filter/gac.html
http://www.malawicichlidhomepage.com/aquainfo/activated_carbon.html
Though now with the common use of a new kind of carbon called ROX .08, which has a very very high clarity and mollasses count I belive that many are agreeing you can go longer.
Personally, I have found using generic LFS carbon and the carbon we get from the Group Buy, that the 2 week rule is correct, I have done a number of tests in my QT tank with carbon in a phosban reactor clearing a tank with Methyl blue I added.
ROX is very expensive, but really really good. You use so much less for the same tank volume, and it lasts *slightly* longer (IMHO), that it is worth the extra. (I am using 1/2 cup, every 2 1/2 weeks a water volume of 120 gallons)
Phil,
The links you posted actually validate Jim's point. GAC's effectiveness is directly proportional to concentration of pollutants, adsorption properties of granules used, and amount of GAC used. Thus, a 6' tower of carbon will last longer (and should be about 36x longer) than same 2" tower, all else being equal. His point was a blanket statement that carbon lasts only 2 weeks is incorrect. If I used only 1 granule in a heavily polluted system, is it going to last me 2 weeks? Maybe it'll last me a day (or more likely only a few minutes). There are many factors and blanket statements regarding how long carbon lasts cannot be made.
The links you posted actually validate Jim's point. GAC's effectiveness is directly proportional to concentration of pollutants, adsorption properties of granules used, and amount of GAC used. Thus, a 6' tower of carbon will last longer (and should be about 36x longer) than same 2" tower, all else being equal. His point was a blanket statement that carbon lasts only 2 weeks is incorrect. If I used only 1 granule in a heavily polluted system, is it going to last me 2 weeks? Maybe it'll last me a day (or more likely only a few minutes). There are many factors and blanket statements regarding how long carbon lasts cannot be made.
2 weeks is again a generalization. The manufacturer of most carbon will suggest 4-6 weeks in a "typical" reef environment based on whatever amount they prescribe. I'm not saying to trust this duration but it is probably the safe amount based on a couple of factors:
1) They have conducted their own study as to the effectiveness of their product in a variety of setups.
2) They are in the business of having you consume the product as fast as possible so you will buy more so their stated duration will probably be less than the true life of the product.
GAC's purpose is to remove inorganics. If you are dosing heavily on products like Iodine, Copper, Strontium, etc. then obviously, the life of the product will be shortened. I don't know where you get this 2 weeks notion from. I'm not saying you're wrong, but there is no data to support your case.
As for the notion of leeching back, this happens only if the carbon is fully saturated. It will selectively "leech" back the least adsorptive compound for something that it has greater affinity for.
1) They have conducted their own study as to the effectiveness of their product in a variety of setups.
2) They are in the business of having you consume the product as fast as possible so you will buy more so their stated duration will probably be less than the true life of the product.
GAC's purpose is to remove inorganics. If you are dosing heavily on products like Iodine, Copper, Strontium, etc. then obviously, the life of the product will be shortened. I don't know where you get this 2 weeks notion from. I'm not saying you're wrong, but there is no data to support your case.
As for the notion of leeching back, this happens only if the carbon is fully saturated. It will selectively "leech" back the least adsorptive compound for something that it has greater affinity for.