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Re: PMDD vs. TMG

"I've been using PMDD for almost a year now and with all this talk about TMG
lately am wondering if I should switch to TMG. From what I've read so far I
understand that TMG contains more trace elements than PMDD. On the other
hand - I can control almost precisely how much of each nutrient I dose in
the tank using PMDD. What other differences are in the products pertaining
to the health of my planted tanks."

For the Tropica ingredients list:


and for the CSM Trace Element ingredients used in PMDD:


and then combining the lists gives this chart:

CSM        CSM+B        TMG
Fe  7.0%        6.53%      0.07%
Mn  2.0%        1.87%    0.04%
Mg  1.5%    1.40%        0.39%
Zn  0.4%        0.37%    0.002%
Cu  0.1%    0.09%        0.006%
Mo  0.05%    0.05%       0.002%
B  0.0%        1.18%        0.004%

(TMG also contains K 0.79%, S 1.01%, which is provided by K2SO4 in PMDD.)

It appears that the units may be not comparable. Perhaps the use of the %
sign in one of the set of numbers is wrong. Or maybe the method of
accounting is different - weight versus volume?  In any case, you can always
increase the concentration of either the CSM or the K2SO4 to get what you
want. I'm dosing just K2SO4 now to see if an Fe limited tank will do better
with green spot/dust algae. (N and P via fish food) Too soon to tell, but
the plants don't seem to miss the trace elements at all. That high dose of K
in TMG may be where it is getting most of its kick. Ten pounds of K2SO4 for
about $20 will last me for many years.