Carbon after medicating
 

So I had to add carbon pad in the Canister after medicating the ick-death matter and its suggested to run it for ~2 weeks....so I was just wondering since its a pain in the *** to take this pad in & out of the canister (Eheim 2213) and carbon looses its function/ usability after short while anyways...couldn't i just leave it in there??? Or will the carbon pad that doesn't work any more so to say then get toxic in some way?

after carbon has soaked up everything and become "full" it will slowly leech things back in the water. i wouldnt let it stay for more than a month and a half.

Carbon does not,cannot ,leach that which it has Adsorbed back into the tank . This is often repeated myth. To release that which it has adsorbed, would require the carbon to be subjected to extreme heat that cannot be produced in the aquarium.
What does happen with carbon is that after it has adsorbed what it can, It becomes less effective and becomes home for nitrifying bacteria.
Is true that due to small amounts ,and perhaps questionable quality ,carbon is not all that effective for long,, but it can't relase crap back into the aquarium. It just stops working.

oO i stand corrected and as always leaned something new here :D

I too read somewhere that it starts being "toxic", but I put my money on 1077's word ;)

The key words are ADSORPTION and ABSORPTION.
Adsorption.. renders that which is adsorbed, to the hard pourous surface of the carbon and it can't easily be released without the extreme temps mentioned,Some say temps in excess of 1800 dgrees F/
Absorption.. is much like what happens with sponge where water is absorbed and also passes through the sponge. Nothingh to hold it,, could relase back into water like wringing out a sponge.
Is why if you use carbon,, you may as well replace it regularly to get it's benefits for it doesn;t last long due to small amounts and or quality offerd in most pre-filled cartridges. If you don't replace it,,then as mentioned ,it becomes part of your biological filtration and if you then remove it,,you also remove a portion of your good bacteria. If you choose not to use carbon at all.. it is therefore wise to add some extra biological media in it's place.

Maybe I miss worded my question about the matter, let me try again :-)

I am fully aware that carbon is only effective so long and then not any more, that's out of question.
Being the Eheim 2213 set up, there's PLENTY bio media as it was in the filter and I run all of my filters w/out carbon.

The reason I needed to add carbon pad into this very tank was ick treatment med's.

And I guess I'm just lazy wanting to know if I can just simply leave it in there till I do the yearly pump maintenance or not. I do understand the carbon will not be beneficial/ working for this long. But I just wanna avoid taking it apart again, making a mess just to get this pad out.

Does that make sense?

Either or. Personally ,I'd just remove it and add more mechanical or biological media. If you have substantial biological media now,, then removing it won't hurt anything.