Replacing Carbon After Medications

[jbrock]

After a course of meds has finished running in you tank, do you put the same carbon you removed from your filter back in or do you replace with new?

 

[Mikey1]

i dont use carbon at all, in any of my tanks/filters....
 
if its still good you can reuse it, but the lifespan of carbon is very short.....in most cases less than two weeks, although that will vary slightly from tank to tank.....

 

[eaglesaquarium]

You would probably have no way of knowing whether the carbon is still adsorbing things or not, so the safer bet would be to use NEW carbon to ensure that you get the meds out... besides fresh carbon will adsorb the meds faster than used carbon.

 

[Chad]

It's my understanding that carbon does not return anything back to the tank but simply loses effectiveness. For that reason I would replace it. Actually it's generally best to remove the carbon from the filter BEFORE medicating so that the carbon does not absorb your medications which of course reduces their effectiveness.

 

[Mikey1]

Actually it's generally best to remove the carbon from the filter BEFORE medicating so that the carbon does not absorb your medications which of course reduces their effectiveness.

 
 
i think the OP did do that.....
 
they are asking if they should return the SAME carbon that they removed, or replace with new

 

[Chad]

Ah, thanks. I missed that.
 
If it was removed then I see no reason not to return the original carbon to the tank. It should still be as good as it was when first removed.

 

[eaglesaquarium]

The question is though, how effective was it before it was removed?  Depending on how long its been in there, it could have been completely used up by this point and will do nothing when returning it.  As I say, I'd go with fresh, leave it in for about 2 weeks to ensure all the meds are taken out, and then toss it.  I wouldn't keep carbon in the filter long term, but that's just me.

 

[Chad]

Right...I agree...it will be as effective as it was. If it was all used up then it will still be all used up, if it was recently put in then it's still just as fresh.
 
Personally I don't have an issue leaving it in because once it's used up it just exists as a bacterial media.
 
Unless you are running a carbon reactor of course in which case the movement in the reactor can eventually create fines that get into the system so it should be removed.
 
Of course as we talked about in the other thread carbon is not required and in some set ups (like when you want tannins) is actually bad so perhaps not returning it at all is also an option?

 

[eaglesaquarium]

I would still think that it would be useful for removing the meds.  I'd do a large water change to lower the meds concentration, then put the carbon in the filter to remove the remnant.  Carbon's long term use can certainly be debated (and has been repeatedly) but I think that in this case, carbon needs to be added to remove the meds.  Whether or not to keep it or toss it is personal opinion.  Scientifically, there's no need to take it out (it won't leech the meds back into the water), but equally there's not a need to keep it in either (unless you are a person who doesn't like tannins, but that's more personal preference than need).  In fact, one could argue that tannins are quite beneficial for most fish in the trade, with some exceptions, most obviously African cichlids.

 

[Chad]

It certainly has more use for a reef tank where water clarity and purity is vital for coral growth.
 
The question I have relates to the medications, I'm hoping you have the answer: why is it a good idea to remove them? Don't they just decay and become inert? Or do they continue on in the water long term?
 
I ask because I don't use medications now and in the past only did so sparingly. In those days if the box said do a water change I did but never really took the time to learn why it might say that and certainly with many ich medications it did not mention it.

 

[eaglesaquarium]

That's an interesting question... I would posit that the reason is related to not wanting to medicate fish that aren't sick, and that the fish (or more exactly what you are treating) may develop a tolerance to the meds, rendering them useless to you in the future.  While the meds probably will breakdown eventually, is that something that you want to have in your tank?  Personally, I'm not a fan of unwanted elements in my water.  Of course, for that reason I have a separate QT/hospital tank, so that I don't need to add meds to my main tank.  
 
 
As far as the science behind it... I'll have to do a little digging.  I may or may not find something for that.

 

[Chad]

It would be interesting to learn more and to see if there is any science done on the subject for aquaria. It's really a subject I haven't thought of until this thread that I have effectively hijacked. Sorry OP.

 

[eaglesaquarium]

I don't think its a hijack at all, in fact, its very much on point.  Do you even NEED to add carbon to the tank at all after the treatment?  If not, then the original question becomes moot.  Just bin the carbon, or put it in, it won't matter either way.  (Of course, I have yet to see any evidence that this is the case.)

 

[Chad]

Well good...I'm glad it's not a total hijack.
 
So...have you seen evidence that this isn't the case? I know a lot of folks on here don't run carbon at all or even keep it around. How many people, I wonder, have used medication and not used carbon to adsorb it?

 

[eaglesaquarium]

I've seen no evidence that it is necessary or that it isn't necessary.  I've just always assumed it was best to remove the meds with carbon, but haven't had to medicate the main tank... just a QT/hospital tank.