Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Probably not. Plant roots do not seem to use sand as well as they do finer materials. I would use pure EC, and when you add driftwood or rocks push them well into the substrate. That can make the substrate a little deeper, especially if you use rocks as a sort of retaining wall, and push the substrate a little deeper at the back.
Smaller plants, usually chosen for the mid and front are OK in shallower substrate, too.