Re: Dupla fertilizers

>>>Now how does one draw the conclusion that "B, Mo, Zn and Cu are still

>Dave Whittaker said....

>>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.

Neil Frank said....

>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. 

George kindly posted an analysis of all three products on March 18, 1996.

>Some of the arguments presented so far are sort of like mixing apples and

The "oranges", the contents of which I was comparing, were the Duplaplant
fertilizer tablets. If you wish to bring "apples", ie Duplaplant-24 drops
into  the equation, the ratios become even smaller. The drops provide much
less Mn, B, Mo, and Cu per unit Fe than the tabs. How you mix the apples
and oranges matters little. You are still left with a shortfall of certain
essential elements. Keep in mind that George tries to maintain a level of
0.1 ppm iron in his tanks and may use laterite which would add even more
iron to the water.

The wild card could be Duplagan water conditioner which, according to the
analysis posted, might (who knows) supply the above micronutrients in
adequate quantities if liberally dosed. Or perhaps a huge amount of iron
is coming out of solution?

Given the analysis of the constituent elements of the above products and
a hundred testimonials about how well the Dupla system worked, I'd still
want to know why.

If I had any reservations about the amounts of micronutrients in a water
supply, I would go with Kevin's mix anyday. Perhaps I was being provocative,
but Kevin's comments were surely fair.


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

>I prepared the following comparison last year, and thought it
>would be a good idea to present it again.


Your value for iron in Duplaplant fertilizer tablets of 0.3 ppm does
not agree with the 234 ppm that George posted which brings us back
to my statement that the "apples and oranges" comparison does not fly.

Maybe this discussion should be on rec.aquaria.plants.

Dave Whittaker                       ac554 at FreeNet_Carleton.CA
Gloucester, Ontario                  dwhitt at magmacom_com