I had a fluval 404 with 4 baskets, but essentially the same as the 306. You can get away with a basket of ceramic media in the top basket which will be enough BB for biological filtration, and 100% Polyfill in the bottom two baskets to give your water that extra polish.
75g Planted Barbs Denison, BlackRuby, Tiger, Albino Tiger, Green Tiger, Cherry, Gold, Checkered, Odessa.
NonBarbs Cardinal, Neon, RummyNose, Bloodfin Tetras, Z. Danios. 1RTS. Amano, Bamboo, Ghost & RCS. 20g Long Shrimp Tank RCS, Tiger, Amano.