I am glad that you have figured out what you want in your own tank. It is yours after all. I personally use a layer of unfertilized potting soil covered by a layer of gravel. The potting soil gives me a decent growing medium while the gravel keeps the potting soil from floating all over the tank and making a mess. My plants are mostly low to moderate in light requirements and I can use the potting soil without added fertilizers or CO2 to grow a good assortment of plants.

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Fishless cycling