I'm curious as well, since I'm nearly done setting up a tank with the same light.
DHG Belem should grow at a snail's pace with no co2. Would look great in your tank. It's a slow grower even WITH co2! Shouldn't add much, if anything, in the way of maintenance.
Where are the fissidens mentioned in the OP? I don't see them in the photos.
Of course, it's sort of cheating to say you're not adding any ferts, since the AquaSoil Amazonia brings quite a bit to the table.