I'm sure this question will have been asked before, but how can Amano use active carbon or charcoal along with giving his tanks regular ferts?

It doses the plants before it's removed, there's some debate whether it removes traces that much or how much. The main part is using it in the start up phase, not all the time. ADA does not add ferts for the first few weeks typically either.

I'll use carbon as well, namely for color removal and Zeolite for NH4 removal.
After a month or so after each is spent, then the materials become bio media and are just left there.

Regards,
Tom Barr

This is from the ADA FAQ list and it should answer a question or two about how Amano seems to use activated carbon.

Aqua Design Amano Co., Ltd (ADA)¡Ý Nature Aquarium

Regards,
Detlef

Cheers guys, so from what i can tell active carbon is used just for the first few weeks it then becomes inactive and becomes a biological filter media.

I'm planning a 200l set up and will have relitivly low lighting 1-1.5wpg and will have mainly crypts and moss in with a few Echinodorus plants I'm planning on having ADA substrate with added Iron or multi bottom and would like to liquid dose K once a week with water changes. Does this sound ok? too much? too little?

Should i not dose any liquid ferts for the first few weeks if i use carbon?