Carbon Media, How Long Does It Last?

[IAmATeaf]

Seen a post elsewhere which raises this question for me. I have carbon bags in both of the lower and 1 in the middle tray. I got the filter second hand so the bags were already there so how long will the bags work for?

 

[fishyfeet]

Seen a post elsewhere which raises this question for me. I have carbon bags in both of the lower and 1 in the middle tray. I got the filter second hand so the bags were already there so how long will the bags work for?

Usually a month so i would remove them, put something else in its place, carbon is a waste of time unless used to remove medication, di

 

[chrisbassist]

carbon does a few things,

1, remove medication (thanks fishyfeet)
2, remove tannins from wood
3, removing cloudiness from water

and it lasts between 2 weeks and a couple of months. certainly no longer

 

[ian]

it will only take up chemicals and other impurities for about 3-4 days, depending on the hardness of your water. It does also leach back what its taken up into your tank after a few months.

 

[IAmATeaf]

So I should really take it out as I've no idea how old it is?

What can I replace it with? In both of the top trays I've got bio rings, in the middle trays I've got more bio rings and what I believe to be a carbon bag, in both of the lower trays I've got what I believe are carbon bags.

 

[chrisbassist]

you can take them out or leave them in, it won't make much difference to the filtration, except taking them out may allow more flow, making the filter more efficient.

if you replace it, i would leave a space to be able to add some more in when you want it (to remove meds, or tannins etc), but the rest could be replaced with more biological media (the rings)

 

[nessar]

sorry to hijack this a bit, but is there any point in having carbon in a filter then?

 

[chrisbassist]

yes

1, remove medication (thanks fishyfeet)
2, remove tannins from wood
3, removing cloudiness from water

(as posted above)

if your water isn't cloudy, you don't have any wood leaching tannins into the water and you're not medicating then theres no point in having it.

 

[Twinklecaz]

yes

1, remove medication (thanks fishyfeet)
2, remove tannins from wood
3, removing cloudiness from water

(as posted above)

if your water isn't cloudy, you don't have any wood leaching tannins into the water and you're not medicating then theres no point in having it.

I think my filter (Fulval) has carbon pads actually attached to the sponges....so I'd have a problem with that coz the carbon will need replacing long before sponges?

 

[chrisbassist]

i wouldn't worry too much, i cant see it doing any harm

 

[OldMan47]

The biggest problem that I am aware of with carbon is that it will gradually break down in your filter and thus will not make a very long lived biological media. Carbon as an ingredient in things like sponges are another matter. Sponges are always decent biological media. The carbon itself, as a chemical removal media, is fairly short lived. Estimates in different places are in the range of 3 days to a month before carbon is exhausted. The concept of them leaching chemicals back into the tank is a half truth. Carbon has a fixed number of sites where things can adsorb to it. Since the number of sites is limited, each new thing that gets adsorbed means that something that has already been adsorbed must be released to make room. If you add a new impurity that adheres better to the carbon than what is already there, the original contaminant will be released back into your water. The carbon does not just sit there bleeding chemicals into your water. It releases chemicals that are not as tightly bound as the new contaminant that it is being asked to remove. The concept that chemicals leach back out is overlooking the fact that the carbon has not been effective for chemical removal for quite some time and it is releasing chemicals because others have come along that it would like to remove from the water. The net effect is that contaminants build up because they are present and the carbon can no longer remove them.

 

[salty pig]

The biggest problem that I am aware of with carbon is that it will gradually break down in your filter and thus will not make a very long lived biological media. Carbon as an ingredient in things like sponges are another matter. Sponges are always decent biological media. The carbon itself, as a chemical removal media, is fairly short lived. Estimates in different places are in the range of 3 days to a month before carbon is exhausted. The concept of them leaching chemicals back into the tank is a half truth. Carbon has a fixed number of sites where things can adsorb to it. Since the number of sites is limited, each new thing that gets adsorbed means that something that has already been adsorbed must be released to make room. If you add a new impurity that adheres better to the carbon than what is already there, the original contaminant will be released back into your water. The carbon does not just sit there bleeding chemicals into your water. It releases chemicals that are not as tightly bound as the new contaminant that it is being asked to remove. The concept that chemicals leach back out is overlooking the fact that the carbon has not been effective for chemical removal for quite some time and it is releasing chemicals because others have come along that it would like to remove from the water. The net effect is that contaminants build up because they are present and the carbon can no longer remove them.

Thanks Old Man.. At last someone has explained it in English. Cheers again mate.