I'm gonna jump in here before this gets ugly and say that this is an issue of differences in husbandry techniques here. You folks across the pond use a different type substrate than we use over here. Ours is a mix of milled sphagnum moss, orchid bark, tree fern fiber, coco coir and charcoal. It's commonly known as ABG. It's a recipe created by the Atlanta (Georgia, US) Botanical Gardens. It provides excellent drainage, as well as nutrition for the plants. The larger chucks give places for things like microfauna and beneficial bacteria to live and still provides enough aeration to prevent any anaerobic bacteria from building up. At least that is what we use for live planted tanks. Some people cover the sub with mosses and leaf litter, but some don't. Guess there's always more than one way to skin a cat