Removing plants from soil substrate

The method I use to remove growing plants from a soil substrate with gravel 
on top is to use a LONG, THIN letter opener (think very thin, dull knife) 
and gently work around the plant's roots.  I do this until the letter opener 
moves freely thru the substrate.   (Background - tank has 1" 
peat/clay/vermiculate topped by ~3" fine (2-3mm) gravel)  When that happens, 
I gently begin pulling on the plant, getting my fingers as close to the 
point where the plant enters the gravel as possible.  If there is 
resistance, then I work the letter opener in the area where I feel 
resistance.  There is no way to remove the complete root system nor is there 
a way to prevent some of the soil from coming to the surface.  Try to 
maximize the first and minimize the second.  Fine gravel traps more soil 
than large gravel.

Good luck,
Rochelle Williams
williaro at ftmcphsn-emh1_army.mil