Ray,

I fear I either do not understand something or I have been underfertilizing
by a lot (or both).

I actually use the Dyna-Gro (7-9-5) fertilizer which you refer to on your
page, and on your page you say that 1 teaspoon per gallon of this formula
results in a total contribution of 235 ppm, which if one reads further down
in your page is somewhere within the norm for Phals "in greenhouse
conditions in bark-based media". I grow in an apartment not in a greenhouse,
in moss not in bar, does that change the formula?

The instructions on this Dina-Gro fertilizer are to use 1/4 to 1/2 teaspoon
per gallon of water for houseplants. The instructions on your Web site seem
thus completely different from those on this fertilizer, unless I am missing
something crucial here.

Reading further in your page I noticed that (if I understand correctly)
lower light levels and temperatures mean that one should shoot for a much
lower ppm target. Does this explain the difference between 1 tsp per gallon
in greenhouse versus 1/4 teaspoon per gallon for windowsill culture?

Following the fertilizer label I use a 1/4 teaspoon per gallon of water. I
use tap water not distilled water (I assume that this also makes a
difference in the ppm). I don't know the water composition in the DC area,
how important is it that I find out? Am I doing something wrong? My Phals
seem to be doing well enough, though I am sure that with more optimal
conditions their potential is much higher. I would really like to get one of
the mature ones to have 2 spikes at once (so far I have had two spikes only
when I bought plants with two spikes, but the following year yielded 1 spike
only), and so I have been trying to improve their conditions, which is why I
would like to know more about optimizing fertilizer now.

Thanks for explaining this.
Joanna

"Ray" wrote in message
...
Most of you are aware of the JavaScript calculator I have on my website
for
determining the concentration of nitrogen, phosphorus, and potassium in
fertilizer solutions. You simply plug in the N, P, and K values from the
label, and the number of teaspoons per gallon you use, and it tells you
the
concentrations in ppm, plus the N, P, & K contributions to the TDS.

After a lot of discussions with the folks at Blackmore (they made the
stuff
for MSU) and Peters, I have concluded that if your fertilizer has a wide
range of minor- and trace elements in it, you can manage your feeding
regimen by simply controlling the nitrogen loading. I have, therefore,
added another calculator to that page which allows one to simply enter the
"N" value from the fertilizer label and the desired nitrogen loading in
ppm,
and it tells you how many teaspoons to add to a gallon of water (and
milliliters per liter).

http://www.firstrays.com/fertcalc.htm

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

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