Activated carbon is not a single product. It can be manufactured so it adsorbs different ranges of molecules. I suspect the activated carbon made for aquariums is the cheapest that can still be called activated carbon, and is highly unlikely to adsorb any of our fertilizers, and may not even adsorb the chelators.
I haven't used any for at least 10 years, probably longer. Its very limited effective life suggests that it has little, if any value for aquarium use, other than for specific, short time problems, like medications. The reason it is recommended by the aquarium products industry should be obvious.