I've been researching this lately(I always like the idea of as natural a cycle as possible) and from what I am finding out a well stocked, and matured Fuge can handle a pretty massive bioload. Mangrove seedlings are the shit it seems. Hopefully I'll have some actual experience with this in a couple months. Seems though if you just focus on what wastes you have(Nitrates and Phosphates) and then look at what will use those things(Mangrove seedlings, Chaeto, etc) with plenty of flow you can make some good things happen.