I would use as much as you can fit into the spot. I like to set up a filtration system by using a coarse sponge, a fine sponge, chemical media then another coarse sponge or whatever media I am using for bacteria growth or biological filter. This way the bio-filter media only needs minimal rinsing. Amount of carbon is variable depending on water chemistry.I only have the white stuff (zeolite) for an emergency or to add to gravel to "sweeten" it for plant growth. The bio-filter should handle any ammonia removal in a cycled (really cycling) aquarium.