My substrate is tahitian moon sand and it seems to be working OK. I push some fert tabs near the roots of the plants that are heavy root feeders. I had already started my tank before I knew much about the possibilities of enriched substrates, and I already had the tms. I really don't want to go mucking about with changing it or adding to it right now (6 ft long 100 gal tank). I'll amend it in the future, I'm sure, but for now, it's fine.