After almost two weeks the bacterial bloom is coming to an end, the water is clearing up and I have better ideas about scaping the tank. Such a huge tank is challenge for a beginner, especially if your LFS gives you wrong information, both about starting an aquarium (use Tetra SafeStart and safely add 50% of the maximum fish for your tank) and about your rock and plants choice. Still more than 90% of the fish survived and water quality is OK now. Of course much will change over the next months. :)