Re:Problem growing Amazon Swords

     >Since this wasn't a controlled experiment, I'm not comfortable saying that 
     >PMDD's did the trick.  Also, I'm not comfortable with the fact that I 
     >don't know why they did the trick - perhaps the tank was limited by K, 
     >perhaps it was limited by Mg, and perhaps it was limited by iron (PMDD's 
     >seem to supply more of all 3 than the Dupla regimen.)
     Long before I discovered PMDD (and the APD), I remedied my plant problems 
     with a product called "Flora Boost (not Tetra's Flora Pride)", purchased 
     from Rivers and Reefs in south Austin.  This rusty-water stuff solved my 
     amazon sword problems (poor growth, pale leaves).  It contained unchelated 
     iron, potassium and, I think, magnesium.  Cheap, too--$5.50 for 16 oz.
     I believe Austin water is poor in K and also in Mg (lots of Ca, though).  
     It is not surprisng it took a few weeks for the PMDD to build up to some 
     "critical level" in your tank.
     Perhaps someone on the APD could recommend an ititial dose of PMDD to get 
     the tank up to working levels, followed by the daily doses to keep the 
     concentrations up.