G'Day all, I have an Eheim 2213 Canister filter, API Bio Chem Zorb, API Nitra Zorb, just wondering what goes where as this will be the first time using Nitra Zorb. From bottom up, it goes Blue Course Sponge (3 or 4 depending on room), then White Filter Pad (1), then Carbon Pad (1), do I then place the Bio Chem Zorb on or the Nitra Zorb? Or do they go in different sections in the filter? Cheers.