Dupla K

I was just thinking of using some of this in my substrate and was wondering
what other's thought about it. Right now all I have is plain gravel not
that plants don't like it infact I have a Slender leaf Amazon sword
(Echinodorus amazonicus) that I thought would never make it past the three
month mark in there but has managed to out last all the other plants I had
in there with the exception of some C. Wendi....Oh ya back to the
         1.  Am I just wasting my time with the Dupla K should I just      
        leave well enough alone... 
          2.  Would I need to tear the entire tank down to use this or     
          can you just drop them into the substrate.... 
          3.  If I place the Dupla K in the gravel does this now mean      
         that I can't vac the part's that I actually can reach... 
Thanks again everyone 
Gary Alness    (misman at hooked_net)---------->