Nutrients & Hydroponics vs Aquaculture

To all,

One might find it interesting that after I searched in the yellow pages
(in Seattle) and talked to everyone in there under both
plants/nursery/hydroponics/etc. that I have reached a question...  No
matter where I went, no store had a micro nutrient mix even close to
what is in PMDD.  After talking to various plant people, it was
interesting to note that the levels of trace element in the PMDD mix vs.
most hydroponic trace mixes are 20 to 1,000 times as much.  Does anyone
know why we would need (for example) 1,000 times more of an element in a
fishtank vs. hydroponics (which seems to me to be the same minus the
fish)?  For example:

	PMDD		A local mix (under various names)
Fe	7%		0.13%
B	1.3%		0.018%
Mn	2%		0.036%
Mo	0.06%		0.0017%
Zn	0.4%		0.018%
Cu	0.1%		0.0077%

The local mix also contains other things (such as nitrogen, potassium,
phosphorus, and calcium) in it, but I'm interested in why the huge

A second note... After browsing the local supply of soil plugs (ie plant
sticks, etc.), what is the best ratio of N/P/K to have?  Some I have
seen on the APD are:

"Aquatic" tabs	20-11-04
Jobe's		14-03-07
"Plant Spikes"	16-02-06
Tetra Initial	01-00-25

A side note is that Jobe's comes in many different ratios, as do many
brands.  I don't know if Aquatic tabs and plant spikes are name brands
or not, but they were listed on the APD, and I tossed them in for
comparison.  So what's the perfect ratio for your substrate fertilizer
(assuming it could be any you want)?  As someone said before...  Why
should we have to pay 10 times more for the same stuff (just not labeled
as for the aquarium)?!
      <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <>< <><
      ><>   If only we could dream like fish...   ><>
      <><   then our souls would be free.         <><
      ><>                                         ><>
      <><   M.P.      pearlsco at u_washington.edu   <><
      ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>