Filter Carbon

[anthony_sydney]

Hi Guys,

How often should the filter carbon be changed?

If you add a new one do you have to go through the cycling process again or can you add two at once leave it for a while and then take out the old one?

Thanks,

Anthony

 

[xingumike]

every 4-5 weeks i believe.

removing it wont cycle your tank no

 

[rdd1952]

Most people don't use the carbon. After about 2 weeks in the tank, it has become saturated and isn't doing anything. The only time you really need it is after using medication so that you can get the medication out of the water. I haven't used it in close to 2 years. I use other forms of media in the filter such as this.

When you change the filter cartridge, you probably will experience a mini cycle. Only change it when it becomes too worn and tattered to function. If possible, move the media from inside the cartridge into the new one.

 

[Chrispixx]

I use other forms of media in the filter such as this.

Matrix Is Great!

 

[Bignose]

Most people don't use the carbon. After about 2 weeks in the tank, it has become saturated and isn't doing anything.

Actually more like around 24-48 hours until saturation. The carbon can exhcange what has been adsorbed on the carbon. Like, it may exchange take up some adsorbed nitrates for tannins, for instance, but all of the adsorbtion sites on the carbon are filled up pretty quickly.

 

[raptorrex]

humm, if you back wash the carbon on a weekly basis, and reactivate it in you oven, every month or so, carbon can last for years! when properly looked after, it actually improves with age.

some people have worries about carbon DE-ADsorbing, collected nasties, however, i have yet to find any proof, that carbon can do so in an aquarium. it takes chemicals, and or heat to do this.

if you use large amounts of carbon it is also worth acclimatising your fish to the new water, there are a lot of things no longer there, after filtering.

goes without saying you remove carbon when medicating your tank.

 

[nmonks]

Carbon is useless in the modern aquarium. Bin it. Replace the space used by carbon with some extra biological filtration. Rely on water changes to remove dissolved organics, or in brackish/marine tanks, a protein skimmer as well.

Carbon is a relic from prehistoric fishkeeping when people didn't believe in doing regular water changes. They thought "old water" was best. Old water turned yellow from the organics, but carbon removed this yellowness, providing a (largely superficial) improvement to water quality.

Carbon and "tonic" salt both exist in the hobby primarily to con inexperienced fishkeepers out of their hard-earned cash.

Cheers, Neale

 

[raptorrex]

fraid i dont agree! there. IMO it can have uses, if used proprly. just wouldnt use it as the main medium.

can you be more perticular in you objections? whilst i hold this view it does not mean that my mind is fixed. and someone with you experience should not just be ignored.

 

[nmonks]

Okay, to explain a little more.

Carbon is sold for doing one thing -- to remove dissolved organic compounds from the water. This is really the only thing it does well. It can be used as a biological filter medium of course, but once covered in bacteria it doesn't adsorb organic compounds any more. So you may as well just use sponges or ceramic media that do the job of supporting biological filtration as well if not better.

Right, the idea behind removing organic compounds is that they accumlate over time and turn the water yellow (hence the word for these organic materials is gelbstoff, from the German for "yellow stuff"). This isn't especially dangerous to your fish, merely unsightly. Carbon removes the organics, keeping your water colourless, which is whay you want. But, is carbon the only way to do this? No, water changes work just as well. Plus, water changes remove not just organics (which are largely harmless) but also inorganic wastes such as nitrate and phosphate, which are unambiguously detrimental to the aquarium. If you are doing weekly 25-50% water changes, there won't be enough organic stuff in the water to turn the water yellow.

In a brackish or marine aquarium organics are removed by a protein skimmer. The advantage here is you don't need to open up the filter to replace the carbon, you just empty the little cup at the top of the skimmer. Skimmers are easier to use, cheaper in the long term, and much more effective. For one thing, you can see how much stuff is being collected, and that way figure out if you are overfeeding your aquarium.

The major downsides to carbon are [1] it is impossible to know when it needs replacing, and [2] awkward to use, and [3] incompatible with most medications.

How often you replace carbon depends on the size of the tank, how many fish are kept, how big those fishes are, what the turnover of the filter is, the size of the carbon grains, how much carbon is used, and so on. Utterly impossible to predict. Hence suggestions about replacing "every week" or "every month" are so unreliable as to be meaningless.

Let's take a safe estimate and replace the carbon every two weeks. Who wants to open up their external canister filter every two weeks? For one thing, that's a pain to do because of the pipes and valves and water that splashes everywhere. If you're like me, you clean the filter as infrequently as possible, usually once every couple of months. I know very experienced marine aquarists who literally clean their external canister filters once a year, if that. Their experience is that once an established filter reaches maximum biological filtration capacity, the advantages of cleaning it out in terms of improved water flow are overshadowed by the loss of biological filtration capacity through the dying back of the filter bacteria when the filter is cleaned.

Finally, you have the carbon versus medication issue. Again, you have to open up the filter and remove the carbon each time you treat your fish. Also, a lot of people don't know about this problem and leave the carbon in and wonder why the anti-whitespot potion failed to work. Other people simply forget the carbon is in there (easily done, and done it myself because I hadn't noticed one of the sponges in one filter I was using was a carbon-impregnated sponge).

Now, there may be specific cases where carbon is useful. Removing medications before introducing delicate fish or invertebrates is certainly one. There may be others. But these are temporary situations or special cases. I can't think of any long-term reason to keep carbon in an aquarium.

So, on balance, while carbon does the things it is sold for (something tonic salt does not!) the problem is that any advantages it confers are trivial compared with the problems it causes. Thus, there's no real point to using the stuff in most aquaria.

Cheers, Neale

fraid i dont agree! there. IMO it can have uses, if used proprly. just wouldnt use it as the main medium.

can you be more perticular in you objections? whilst i hold this view it does not mean that my mind is fixed. and someone with you experience should not just be ignored.

 

[raptorrex]

Okay, to explain a little more.

Carbon is sold for doing one thing -- to remove dissolved organic compounds from the water. This is really the only thing it does well. It can be used as a biological filter medium of course, but once covered in bacteria it doesn't adsorb organic compounds any more. So you may as well just use sponges or ceramic media that do the job of supporting biological filtration as well if not better.

Right, the idea behind removing organic compounds is that they accumlate over time and turn the water yellow (hence the word for these organic materials is gelbstoff, from the German for "yellow stuff"). This isn't especially dangerous to your fish, merely unsightly. Carbon removes the organics, keeping your water colourless, which is whay you want. But, is carbon the only way to do this? No, water changes work just as well. Plus, water changes remove not just organics (which are largely harmless) but also inorganic wastes such as nitrate and phosphate, which are unambiguously detrimental to the aquarium. If you are doing weekly 25-50% water changes, there won't be enough organic stuff in the water to turn the water yellow.

In a brackish or marine aquarium organics are removed by a protein skimmer. The advantage here is you don't need to open up the filter to replace the carbon, you just empty the little cup at the top of the skimmer. Skimmers are easier to use, cheaper in the long term, and much more effective. For one thing, you can see how much stuff is being collected, and that way figure out if you are overfeeding your aquarium.

The major downsides to carbon are [1] it is impossible to know when it needs replacing, and [2] awkward to use, and [3] incompatible with most medications.

How often you replace carbon depends on the size of the tank, how many fish are kept, how big those fishes are, what the turnover of the filter is, the size of the carbon grains, how much carbon is used, and so on. Utterly impossible to predict. Hence suggestions about replacing "every week" or "every month" are so unreliable as to be meaningless.

Let's take a safe estimate and replace the carbon every two weeks. Who wants to open up their external canister filter every two weeks? For one thing, that's a pain to do because of the pipes and valves and water that splashes everywhere. If you're like me, you clean the filter as infrequently as possible, usually once every couple of months. I know very experienced marine aquarists who literally clean their external canister filters once a year, if that. Their experience is that once an established filter reaches maximum biological filtration capacity, the advantages of cleaning it out in terms of improved water flow are overshadowed by the loss of biological filtration capacity through the dying back of the filter bacteria when the filter is cleaned.

Finally, you have the carbon versus medication issue. Again, you have to open up the filter and remove the carbon each time you treat your fish. Also, a lot of people don't know about this problem and leave the carbon in and wonder why the anti-whitespot potion failed to work. Other people simply forget the carbon is in there (easily done, and done it myself because I hadn't noticed one of the sponges in one filter I was using was a carbon-impregnated sponge).

Now, there may be specific cases where carbon is useful. Removing medications before introducing delicate fish or invertebrates is certainly one. There may be others. But these are temporary situations or special cases. I can't think of any long-term reason to keep carbon in an aquarium.

So, on balance, while carbon does the things it is sold for (something tonic salt does not!) the problem is that any advantages it confers are trivial compared with the problems it causes. Thus, there's no real point to using the stuff in most aquaria.

Cheers, Neale

fraid i dont agree! there. IMO it can have uses, if used proprly. just wouldnt use it as the main medium.

can you be more perticular in you objections? whilst i hold this view it does not mean that my mind is fixed. and someone with you experience should not just be ignored.

thanks neale. gona need time to think this through.

 

[andywg]

humm, if you back wash the carbon on a weekly basis, and reactivate it in you oven, every month or so, carbon can last for years! when properly looked after, it actually improves with age.

This is just bunkum.

From this article by Timothy Hovanec, myth number 9.

Activated carbon is made by subjecting a base material that is high in carbon content to very high temperatures (about 2,000°F) in a low oxygen atmosphere. The oxygen content is important because too much will cause the material to burn completely resulting in no product; while too little oxygen means no burning at all and, therefore, no activation. Activated carbon that has had all its adsorption sites filled can be reactivated by going through the process again at the same high temperatures. But some people assume they can reactivate the carbon by simply placing it in their kitchen oven at the highest temperature setting, typically 500 to 600°F. This is false. It may burn off some organic material trapped in the carbon but it will not reactivate the adsorption sites. Further, there is a fire hazard potential if the carbon ignites, as you would basically be putting a barbecue in your oven.

Unless you have a seriously hot oven, or a pretty decent pottery kiln, you are not going to be recharging carbon.

 

[raptorrex]

sorry andy but you can reactivate carbon at temps from 177- 700 degrees. thats another phalicy like carbon deadsorbing. lol though you may have information that i have not yet seen. like neale said, a lot of the buncum about carbon is down to sales figures, and that is one of them.

the temp needed goes up according to the type of compounds that the carbon has adsorbed.

something else struck me about neales post. he stated that when carbon is goarged, it turnes the water yellow. cant see that, if it is full it simply no longer removes these compounds from the water, and as i have said there, as far as we can tell there is no scientific proof that carbon can deadsorb in an aquarium. as you just pointed out, it takes a lot of heat to do that!

please do not consider this as an assumtion that you are both wrong, its just that, as yet, i can find no scientific refference to these points, the information, and indeed the chemistry invloved, are so different to the advice given in most fish sites on this subject.

it would help if i could find a single proveable example of any form of deadsorbtion, within an aquarium enviroment.

 

[andywg]

sorry andy but you can reactivate carbon at temps from 177- 700 degrees. thats another phalicy like carbon deadsorbing. lol though you may have information that i have not yet seen. like neale said, a lot of the buncum about carbon is down to sales figures, and that is one of them.

...

please do not consider this as an assumtion that you are both wrong, its just that, as yet, i can find no scientific refference to these points, the information, and indeed the chemistry invloved, are so different to the advice given in most fish sites on this subject.

Here's my problem.

I linked to an article by a man who possesses a Ph.D and spends his life studying the way we can filter aquarium water. This article was published in a magazine, meaning it had to be factually correct or he would look somewhat silly and it would impact badly on his career.

You are making sweeping statements to the opposite without linking to any sort of authority.

With the greatest of respect, I am more inclined to believe something written by Dr Hovanec than you about how filters interact with our aquarium water.


Should anyone wish to read a little more on the credentials of Timothy Hovanec, I suggest reading the brief bio of him here. Of some note is the fact that he was the first person to demonstrate that bacteria of the phylum Nitrospira were the active nitrite-oxidising bacteria in aquatic systems such as aquaria, as well as setting up an aquarium research lab and helping develop the bio-wheel and Bio-Spira

 

[raptorrex]

with the greatest of respect andy he offers no proof, just his opinion. and it is a link to a commersial site, something we have both stated is often far from reliable. i would never impune this mans reputation. but you pointed out i didnt link to any information backing my comments, though you did, they the comments were not backed up by any science.

again if anybody can supply some scientificaly provable information that would be different. but try as i might, i can find none.

however: taken form http/www.homedistiller.org/polish.htm

Heating in an oven to 160 deg C is quite sufficient to clean used carbon to the extent that it can be used again, particularly when the carbon is first soaked in water to provide active flushing with steam as it boils. Of course, this will not release all the adsorbed molecules … heating to a much higher temperature in an inert atmosphere is needed to do that thoroughly … but 90+% efficiency is good enough for all practical purposes, and has been used as a cost-effective recovery process by sugar refineries ever since 'white' sugar was processed.

 

[fozziebear]

id just like to say, activated carbon has a very large surface area for beneficial bacteria to grow on, so you can use it as a bio filtration method, and it will be very effective, i dont think there is any need for someone who already has a carbon filter (with a mechanical sponge), to go out and replace the carbon purely for the purpsoe of bio filtration, because if its been left in there for more than 4 weeks or so it will be doing the job fine anyway.