I've never had a substrate go bad. I even set one up, filled the tank, and let it sit for a year before planting a couple dwarf sag and a crypt spiralis in the tank, I was a little distracted at the time. I also put some rotala rotundifolia on the substrate and held it down with a rock. All three plants took to this anoxic substrate, spread, and turned it over. You have to remember I don't use a topsoil with any organic material in it, it is mineralized.
Actually the ten gallon tank that I show the picture of in another thread is that tank, with that same substrate today, some of the plants are gone and others are planted in there now.
My substrates are lasting, at last count which is present day, 9 years. And that tank had a massive die off because of a heater malfunction, is got stuck on. However, everything that had below gravel biomass came back after a water change. I was very glad to see that because my 9 year old Lace plants are in that tank (at the time they were 6). Other plants that came back are Crypt parva, Crypt spiralis, Crypt walkerii, Crypt willisii, and an Amazon sword I don't know the species of.
Aquascape? I'm a crypt farmer.
It's a fine line between fishing and standing on the shore looking like an idiot.
That IS an aquascape, it's titled "The Vacant Lot".