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,