I'm planning on tearing down my tank soon and want to use a better substrate for my plants (as opposed to just gravel). I found laterite but it's kinda expensive. I wanted to mix 1 lb of laterite with 2 lbs of vermiculite (well wetted) in the bottom third of my gravel. I have 160 watts of light over a 100 gallon, no substrate heating, and DIY CO2. Will it work? Thanks in advance, Roni