Echinodorus Osiris

Hi all,
although I don't have access to the internet (yet), I have been 
following your discussions since May 95 through downloads provided to me
 by Franc. A heartfelt 'thanks' to all of you who made my first
 tank a spectacular experience.

Yet I do have a question to which I cannot find an answer in all the 
megabytes of downloads or in my books:
My Echinodorus osiris, bought as "ruffles", is a far cry from the one 
on the cover of Ines Scheuermann's Aquarium Plants Manual. It has 
six or seven leaves (2.5"x7"), reddish when immature, on 6-8" l
ong stalks. When an additional leaf forms, the oldest leaf "shuts 
down", dying off from the tip as fast as the new leaf grows. This
 suggests to me a deficiency of some movable nutrient. But which?

Tank information:
100cmx50x50, effective water colum 16", 210 l (60 gal) water volume
2" silica gravel w/laterite, 2" w/out, Dennerle style UG heating 50W
30l water change every two weeks (1/3 tap, 2/3 destilled)
daily Dupla24 drops to keep iron at <.2 ppm 
potassium sulfate added when older leaves become spotty (2 ml of 1 
molar KSO4/gal)
potassium nitrate added to keep NO3 at 5 ppm (fish don't poop enough)
MgS04 added w/water change, Phosphate tests minimal
pH 6.9, KH 5-6 degrees, C02 injection, temperature 75-80 dF
2 - 160 W Wonder(spot)lights (colour adjusted mercury vapour), 10 
hours /day
overflow corner filter (sponge) plus sleeve on powerhead.
Fish get fed a tablespoon of flakes or less once per day, or a few 
pieces of brine shrimp. 

Almost everything else grows just fine: 
best: H.polysperma "green", Limnophila aquatica, Aponogeton 
elongatus, Ceratophyllum demersum, E. tenellus v.tenellus, 
E. pontederiofolia, Cryptocoryne wendtii, C.petchii, Riccia,
ok: H.polysperma "red", H. difformis, Bacopa monieri, B. carolinia, 
Sagittaria sp., Rotala rotundifolia, Anubias barteri nana, Lilaeopsis 
n.-z., Microsorum pteropus, Cryptocoryne ciliata, 
poor: E. osiris (directly under the light), Vallisneria sp. Rotala 
macandra (potted, directly under the light),

Algae: Since adding SAEs, brush algae is almost gone. All I get is a 
bit of spot algae on the glas, some "staghorn" on the java moss.

BTW, Tetra plant tabs, added near the roots of the Osiris, don't do 
much. Neither do threats with the compost heap.

I hope someone can help me with this. Thanks again.

Mike Eckardt
Waterloo, in the Canadian Winter Wonderland:
"Every winter I wonder what I'm doing here."