These are aquarium plants that can grow on a hard surface and not in the gravel, they actually prefer a hard substrate. Some species actually actively hate to be grown in a substrate, especially if it’s the enriched aqua soil types. Therefore you will do great by them if you attach them to a hard surface and feed them through the water column. Most species that fall into the category of "epiphyte" are very robust and undemanding aquatic plants, which also get along with low light and little nutrients. Nevertheless, a good supply with carbon via CO2 and/or liquid fertilizer will benefit the vitality and growth of these rather slow-growing aquarium plants. Most of them love extra addition of iron to the water column.