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Re: PMDD dosing

>>>>> Jonathan Uy <5js at durian_usc.edu.ph> (here: "JU"),
>>>>> on Tue, 20 Jan 1998 17:19:31 +0800,
>>>>> pondered the meaning of life, then wrote down:

    JU> I like to try dosing KNO3, MgSO4 and K2SO4 separately from the chelated
    JU> trace element mix.  I think I don't have enough macronutrients with the
    JU> standard PMDD formula.  Can somebody give me a recipe for a concentrated
    JU> stock solution which I can add during water changes which will ensure
    JU> enough supply for my plants?  Thanks.


Read the original paper by Sears and Conlin that described PMDD in _The Krib_ 
website.  It explains how you're supposed to tweak the PMDD ingredients.  

The PMDD "formula" that many seem to take as dogma was meant as a generic 
recipe for a generic tank.  As you've discovered, the intent was to use it 
as a base to begin adjusting the right amount of each nutrient you need for 
your tank and adapt the recipe.  The paper explains the process the authors 
used to tweak the nutrients accurately.  

Also, search the archives for comments and anecdotes by the authors and others 
on dosing only during water changes.  I do believe there were some discussions
on final nutrient concentrations including formulas for dosing concentrations
based on percentage and frequency of water changes.

Carlos E. Munoz <cmunoz at crystal_cirrus.com>

AGA pitch for Erik Olson: 
    "Join the Aquatic Gardeners Association!  You know you want to!"