hey man, you and I are in a similar situation.
in my 55 gallon, I ran a dirt capped with gravel, moving plants and clearing unwanted new sprouts always pulled some dirt up to the top layers.
so in the 75 gallon I am getting ready to start up. I got black diamond blasting media from Tractor supply, it is of course black. people have good success with it.
you can drop some osmocote fertz then put the media on top of it for the heavy root feeders I hear.
I won't have any experience with it until I get my tank up and running.
you can check up on that and see if its for you.