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.  After reading through most of the net posts on laterite, it
seems the primary advantages of laterite are as a chelating region and its
ability to remove phosphates from the water column.  If vermiculite has a
higher CEC than laterite, it would serve adequately as a chelating source.
I wanted to mix 1 lb of laterite with 2 lbs of vermiculite (well wetted) in
the bottom third of my gravel, thereby obtaining a substrate with a high
CEC, phosphate removal capability, and lower cost. I have 160 watts of light
over a 100 gallon, no substrate heating, and DIY CO2.  Will this work?    

                                                Thanks in advance,