Re: PMDD Formula ? Good stuff to grow with

["James Purchase" <jppurchase at rogers_com>]

Scott H. wrote:
"About the only really clear thing is Tom's guideline's on
fertilizing, imo   ;-)"

If Tom (and this list in more general terms) are responsible for helping
more people become more successful aquatic gardeners, that's a very good
thing.

The APD can sometimes be a very technical forum and I'm sure that it can
intimidate the daylights out of someone without a scientific background. As
has often been pointed out, this isn't rocket science (even though some of
the chemicals we use have applications in that area).

But I feel that it is better, in the long run, to figure out a way to
explain the basic science behind a question and provide someone with the
skills they need to work it out for themselves, rather than just give them a
pat answer (i.e. add 1/2 tsp. of X per week). While the latter might seem
simpler, people end up doing things they really don't understand the reasons
for.

And, unless people learn how to find the answers for themselves to the many
questions that a new aquatic gardener has, there is going to be an awfully
long line of people asking Tom the same questions time after time.

In some ways, I feel that there is a concerted effort on the part of some
people to "dumb down" the hobby - reduce things to the simplicity of a cake
mix. To some degree, this can work, up to a point, but it can be carried too
far.

One disturbing side effect of the "approximation school" is that newbies
might get the idea that it is REALLY O.K. to be sloppy - "hey, no need to
worry about being exact, if 1/2 tsp. is good, 1 tablespoon ought to really
get things going". Sort of like the way Emeril throws around his special
seasonings and garlic.

When this is carried over into such basic practices such as regular water
changes (oh, I'm too tired to do the water change this week.....I'll let it
slide...) and combined with the tendency (in my not so humble opinion) for
over fertilization of a lot of nutrients in tanks which really don't need
nor can consume those levels, this can lead to toxic levels of some elements
developing and producing problems of their own.

For example, Copper is an essential trace element which is toxic if present
in excess. The levels which are considered "excessive" can vary, depending
upon the plants you are growing and what animals you have in your tank, but
in general anything approaching 0.5 mg/L (ppm) is not healthy in the long
term. If someone who uses quality fertilizers such as Seachem Flourish and
Flourish Trace on a regular basis, according to manufacturer's directions,
but who fails to carry out regular partial water changes, it won't take too
long for Copper levels in the tank to zoom past the 0.5 mg/L level. Not
taking uptake by plants (which, to be realistic, would have to be factored
in) into account, it would only take 13 weeks of dosing without water
changes to result in potentially damaging levels of Copper in the tank. This
isn't a fault in the formulation of Seachem's products, it is a reminder to
perform regular maintenance (i.e. do water changes).

If someone using a bulk trace element mix is following the "a pinch of this
and a smidge of that" school and also fails to heed the practice of water
changing, they might run into difficulties a lot sooner and you aren't
really doing them nor their plants any favors by encouraging the "dumbing
down" or removal of too much detail from a newbie's database.

Simplicity is good, but any good baker will tell you that ingredients ought
to be carefully measured, especially by a beginner. Good habits learned
early can last a lifetime. So can bad habits (as my mother loved to point
out to me).

I hope that all APD'ers have a Happy (and hopefully more precise) New Year!

James Purchase
Toronto