A search for this subject didn't really turn up any threads, just mentions here and there. My question is this: I have an Emperor 280 on a 46 gallon tank. I have the carbon/floss cartridge that comes with it, along with the custom cartridge which I filled with a carbon/zeolite mix. But I seem to read more and more that carbon is worthless unless one has an ammonia problem or is trying to get rid of tannins or medicine. I don't have any of these problems. I was thinking of taking all that crap out and using a cut filter sponge with filter floss in front of it, and maybe some of those ceramic ring thingies to supplement the bio-wheel if there is room. What does everyone think of this? Is carbon useful for a cycled aquarium with no medicines or tannins?
Utility of Carbon
- Thread starter mrbigmuscles
- Start date
there are a variety of pollutants dissolved in any aquatic environment containing biological life. dissolved ORGANIC compounds (DOC's) include proteins, amino acids, phenolic compounds, pheromones and other metabolic byproducts which are continuously being exhausted into the aquarium water by the fish or other aquatic animals. if these organic substances are allowed to become concentrated, they will negatively impact fish feeding rates, growth rates and reproduction rates, they will lower immune system activity and promote blooms of pathogenic bacteria in the water.
these DOC's can be controlled by water changes, however a pretty rigorous maintainance schedule is required. i recommend maintaining your nitrate levels at less than 10 ppm (the less the better) since doing so will concurrently facilitate a low level of DOC's, something which you cannot test for. THE PROBLEM is that a great many aquarists don't adhere to such a maintenance schedule and don't test for nitrates.
if you are not managing your nitrates and thus your DOC levels, chemical filtration is perhaps the best method for you. carbon filtering removes DOC's via adsorption. as the aquarium water flows through the carbon medium, the Dissolved Organic Compounds come into contact with the surfaces of the carbon granules where they become attached. this is ADsorption --- not ABsorption. some DOC's are adsorbed directly, whereas others combine chemically with already-captured substances. when the surfaces of the carbon become saturated, it stops working and needs to be replaced with new carbon.
one needs to recognize that there are many types of carbon sold for aquarium use but VERY FEW of these are actually capable of adsorption in water. only HIGH QUALITY ACTIVATED GRANULAR carbon which has been degassed in an oxygen oven at temperatures close to 2,000 degrees Fahrenheit is functional --- anything else is worthless. i can recommend Marineland activated granular carbon in this regard though there may be others. degassing enlarges the apparent surface area of each carbon granule, thus greatly increasing the adsorptive capacity. look for activated carbon which is phosphate free. a great many carbon grades are washed with phosphoric acid in an effort to support the adsorption sites since this is cheaper than degassing. this phosphate will leach into your aquarium water and can reult in a major algae problem.
deep beds of Granular Activated Carbon (GAC) are always more effective than shallow ones of equal area. also, for a given amount of GAC the smaller the granules, the greater the adsorptive capacity. generally, there needs to be 4 to 10 grams of GAC for every gallon of water depending on stocking density. such carbon beds typically last only a month at best and more typically 2-3 weeks since most hobbyists tanks are overstocked. if your filter uses prepackaged cartridges containing carbon, realize that these cartridges typically contain poor quality carbon and if quality carbon is used, only 20 percent or less of the recommended amounts of GAC is present. you can slit open the cartridge and fill them with more GAC but many pad filter types simply will not hold that much. thus, the carbon in the vast majority of filter pads on the market simply are not functioning. therefor why pay for it.
in a filter, the GAC should always be placed after the mechanical filtering medium otherwise, the particulates in the water will quickly coat the surfaces of the GAC, rendering it useless.
so what's the bottom line? if you're going to use activated carbon, you've got to use QUALITY material, you've got use ENOUGH of it to work and you've got to CHANGE IT often enough to keep it functional. a weekly water change schedule taylored to your bioload will work equally well however and is certainly less expensive.
these DOC's can be controlled by water changes, however a pretty rigorous maintainance schedule is required. i recommend maintaining your nitrate levels at less than 10 ppm (the less the better) since doing so will concurrently facilitate a low level of DOC's, something which you cannot test for. THE PROBLEM is that a great many aquarists don't adhere to such a maintenance schedule and don't test for nitrates.
if you are not managing your nitrates and thus your DOC levels, chemical filtration is perhaps the best method for you. carbon filtering removes DOC's via adsorption. as the aquarium water flows through the carbon medium, the Dissolved Organic Compounds come into contact with the surfaces of the carbon granules where they become attached. this is ADsorption --- not ABsorption. some DOC's are adsorbed directly, whereas others combine chemically with already-captured substances. when the surfaces of the carbon become saturated, it stops working and needs to be replaced with new carbon.
one needs to recognize that there are many types of carbon sold for aquarium use but VERY FEW of these are actually capable of adsorption in water. only HIGH QUALITY ACTIVATED GRANULAR carbon which has been degassed in an oxygen oven at temperatures close to 2,000 degrees Fahrenheit is functional --- anything else is worthless. i can recommend Marineland activated granular carbon in this regard though there may be others. degassing enlarges the apparent surface area of each carbon granule, thus greatly increasing the adsorptive capacity. look for activated carbon which is phosphate free. a great many carbon grades are washed with phosphoric acid in an effort to support the adsorption sites since this is cheaper than degassing. this phosphate will leach into your aquarium water and can reult in a major algae problem.
deep beds of Granular Activated Carbon (GAC) are always more effective than shallow ones of equal area. also, for a given amount of GAC the smaller the granules, the greater the adsorptive capacity. generally, there needs to be 4 to 10 grams of GAC for every gallon of water depending on stocking density. such carbon beds typically last only a month at best and more typically 2-3 weeks since most hobbyists tanks are overstocked. if your filter uses prepackaged cartridges containing carbon, realize that these cartridges typically contain poor quality carbon and if quality carbon is used, only 20 percent or less of the recommended amounts of GAC is present. you can slit open the cartridge and fill them with more GAC but many pad filter types simply will not hold that much. thus, the carbon in the vast majority of filter pads on the market simply are not functioning. therefor why pay for it.
in a filter, the GAC should always be placed after the mechanical filtering medium otherwise, the particulates in the water will quickly coat the surfaces of the GAC, rendering it useless.
so what's the bottom line? if you're going to use activated carbon, you've got to use QUALITY material, you've got use ENOUGH of it to work and you've got to CHANGE IT often enough to keep it functional. a weekly water change schedule taylored to your bioload will work equally well however and is certainly less expensive.
Are you stating that you cannot test for DOC or that you cannot test for low levels of DOC?liv2padl said:
http://www.marinedepot.com/md_viewItem.asp?idproduct=SF1141
Salifert makes a DOC test kit. It doesn't work, then?
Roan
i tried that kit awhile back and found that it wasn't very accurate. trying to distinguish between the color produced by 1 drop vs. 2 drops or 2 drops vs. 3 drops is difficult at best. the only really accurate tests are found in the laboratory, not the home. in any event, simply changing your water sufficient to keep nitrates at or below 10 ppm is easy and gives the results any aquarist should seek to maintain.
Hrm, then how come my nitrates are at 10 and my phosphates are off the chart? Or is phosphate testing inaccurate as well?liv2padl said:
Roan
why would nitrate and phosphate have anything to do with each other? it's certainly possible to have high PO4 and low NO3 ... you may be using fish foods with very significant levels of phosphate, you may be using carbon with high levels of phosphate, your tap water may contain phosphate ... there's lots of reasons. as fo the accuracy of your phosphate kit .. i have no idea, but there are PO4 absorbing pads you can add to your filter.
DOC's are a different story since they're presence in a tank is not related to outside sources but rather, from fish metabolism.
DOC's are a different story since they're presence in a tank is not related to outside sources but rather, from fish metabolism.
Carbon really isn't necessary. I was conditioned into thinking that you had to have carbon in the tank, I mean, all the filters sell carbon inserts so you need them right?!?! It was really hard for me to not use it anymore. However, many months later I am carbon free and have a very happy clean tank 
Hi everybody,
1.I must totally agree with Holly. I do not see any need of using carbon unless You had medication in Your tank before.
2. I believe that You need some NO³ if You have real plants in Your tank. If You have plants I would suggest 20 mg/l NO³, more is an indicator of problems.
3. The most important thing in filtermedia is surface. The more You have, the more bacteria (nitrosoma) will grow in the filter. That meens also to clean only then the filter if wateroutput is almost zero.
4.PO4 is from my perspective either a problem of the water You use ore You feed too much. Well, I also know people who are using nutrition for normal outside plants which is definetely not suitable for underwater-plants.
1.I must totally agree with Holly. I do not see any need of using carbon unless You had medication in Your tank before.
2. I believe that You need some NO³ if You have real plants in Your tank. If You have plants I would suggest 20 mg/l NO³, more is an indicator of problems.
3. The most important thing in filtermedia is surface. The more You have, the more bacteria (nitrosoma) will grow in the filter. That meens also to clean only then the filter if wateroutput is almost zero.
4.PO4 is from my perspective either a problem of the water You use ore You feed too much. Well, I also know people who are using nutrition for normal outside plants which is definetely not suitable for underwater-plants.
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