What’s the latest opinion on activated carbon in a planted tank? There is conflicting opinions on the APD. I would like to get rid of tannins from my aquasoil.

Let's take a look.
Removes organics, that's good.
Removes NH4, that's great.
Removes yucky yellow color from tannins, that's even better.
Supposely removes traces, that's bad.
Turns to biomedia after 1-2 months.

Amano uses it and seems to think about the same things about it.

I'd give it two big green thumbs up.
Some ADA AS is more tanninsish than others BTW.


Regards,
Tom Barr

Seachem purigen is a good alternative to carbon if you are concerned about traces. I like using it in my Discus tank to control organics that build up despite the weekly 80% water changes. It has a water clarifying effect just like carbon, but it will not take the traces out of the water. Another thing that I like about it is that it can be recharged with bleach when it is exhausted and used over and over again.

I use Purigen in marine tanks.
AC is cheaper and better for biomedia later.
I sort of doubt the trace ferts removal though personally.

They may be affected a little, but it's something that is small and would be hard to quanatify.

I've used it and never noted any significant difference.
Seems the Purigen wil last longer also, not remove them, but is not as a good biomedia later and cost a bit more.


Regards,
Tom Barr

I find purigen cheaper in the long run because I can reuse it over and over endlessly- at least so far. True that is is not a good biomedia, but then again thats what true biomedia is for. I guess it all depends on your application. For myself I have two filters one for biofiltration and the other for mechanical/ chemical so it works for me. I guess it also depend on if you plan on only using the carbon once (like when setting up a tank) and then leaving it in there, then yeah Purigen would be a waste for that I think. It's just a good alternative worth mentioning.

Yes agreed.

The only issue I have a problem with is the notion that traces are really removed by carbon and given it last aboput month anyway, then goes south, what's the issue?

The effects are only termporary at best and not significant at worst.
I think it's toughb to shwo there's a big issue with this unless you add AC all the time etc, I think Zeolite for NH4 removal is better.
For tannins, water changes/AC works very well.

Then you remove the media, then add the traces, fairly simply if you have a sump etc.

Purigen and AC both can be used in that manner.

Regards,
Tom Barr

I tend to use AC incidentally. Usually powdered as an overlay with a diatom filter if I can't get a new setup to clear. Usually it will clear on its own.

Where I get strung out on AC is the Vast difference in qualities available over the counter. I tend to buy by the bucket or barrel, but I just don't use it often enough these days to justify buying a 55 barrel.

Given our local water quality I tend to strip everything and reassemble it as needed, but I'm forced to admit it's anal and likely a complete waste of time. Old habits die hard ! Plants are pretty resilient, and do better work than I do.

I still think AC makes a fine high porosity matrix for denitrification, so it may very well be a win/win situation.

Should the AC be switched out every 1-2 months also like my filter instructions tell me to? Or should I just put it in there when I first start the tank then leave it in there for the life of the tank....

Generally only for the start up only.
Leave it in there.

Rarely is it of use later.

Regards,
Tom Barr

I use it maybe once a month to clear the water i leave it in maybe 2 days then remove it when water is crystal clear. I do a 50% water change a week on sunday that usually is enough to do the trick other than the small amount of cheap carbon in my hob filter pad. In my testing i dont notice any changes in my water testing if you use it remove it when its spent.