Re: Dupla Fertilizers

>From: ac554 at freenet_carleton.ca (David Whittaker)
>Date: Fri, 22 Mar 1996 06:01:03 -0500
>Subject: Re: Fertilizer comparison

>>Let's review the Dupla analysis yet again:
>>Duplaplant fertilizer tablets
>>- -----------------------------
>>Ca   5.5 ppm    Mg   0.3 ppm    Na 116.0 ppm   K  2490.0 ppm    P    0.3 ppm
>>Al   0.4 ppm    Fe 234.0 ppm    Mn  36.8 ppm    Ti   0.6 ppm    Cu   0.2 ppm
>>Zn   0.6 ppm    Ni   3.7 ppm    Mo   0.7 ppm    Cd  <0.1 ppm    Si   5.7 ppm
>>Cr   0.1 ppm    Sr  <0.1 ppm    B    6.7 ppm    Pb   0.1 ppm    V   <0.1 ppm
>>Now how does one draw the conclusion that "B, Mo, Zn and Cu are still
>Not missing but maybe in short supply.
>The concentration of boron for instance in dry tissue in most higher
>plants is about 20% that of iron. 
>Now review the Dupla analysis again and note that the ratios of Cu,
>Zn, B and Mn to Fe are substantially lower than dry tissue ratios.

It is IRRELEVANT to evaluate each of the three Dupla Fertilizers separately
and independently by ratio-ing their trace elements to iron.  What is
important is the final concentrations in the aquarium, and there is
insufficient information contained in ANY of the posted information to make
this determination. What is missing is the relative doses of the drops, the
tablets and the water conditioner. 

Some of the arguments presented so far are sort of like mixing apples and
oranges. It is unfortunate that the discussion has turned sour. :-) Allow me
to illustrate why dosing informatin is important.

Suppose you had a 6 ounce can of frozen orange juice concentrate, a six
ounce can of frozen apple juice concentrate, a one liter bottle of apple
juice and a 1 liter container of fresh squeezed orange juice. Mix the frozen
orange juice concentrate with the straight apple juice (mixture A) and the
same with the apple juice concentrate with the fresh squeezed orange juice
(mixture B). It is clear that mixture A is mostly orange and B is mostly
apple. Let's say that we have something like

Mixture A               Mixture B
Or      9 parts         Or      1 part
Ap      1 part          Ap      9 parts

(note: these could have been presented as ppm, but the numbers would be much
higher. :-)

Now ratio the percentages of each to orange. 

Mixture A               Mixture B
Or      1.0             Or      1 
Ap      .11             Ap      9.0 

This shows that Ap is in relatively short supply in mixture A.
This is analagous to Boron in Duplatabs.

But what if I told you that I was going to add these mixtures to two 10
liter aquariums. In the first aquarium, I would add 9 ml of mixture A and 1
ml of mixture B. And you guessed it, in the other aquarim, I would add 1 ml
of A and 9 of B. What you end up with is exactly the same concentrations of
apple juice in both aquariums.

It just shows that you can mix apples and oranges. :-)

BTW, I don't use Dupla products, but I am fairly certain that they provide
the proper amounts of each nutrient.

Neil Frank                 Aquatic Gardeners Association,  Raleigh NC