[houseofcards]

If your just starting the tank up, it's many times beneficial to use carbon until the bio-filter matures. It will remove organics that would have turned into ammonia. It's affect on ferts is really not an issue. It's more important to keep the water as clean as possible to prevent algae.

 

[houseofcards]

It's more valuable to use carbon in the beginning then not to use it. The biggest issue at startup is algae, carbon can help. You use it for a few weeks or so until the plants start growing and the bio-filter matures and then you can remove it.