E. Cordifolius not growing...

I have a 30gal planted tank w/ramant C. wendtii (I can't control it!?) and
Giant Hygro doing well, as well as C. retrospiralis (maybe - I forget, but
it looks like that var.) that's taking off after more than a year or barely
sustaning itself.

I dose CO2 from a 5lbs bottle via 2 Tetra "Bells" and add Hawiian Marine
FerroVit and just started (< 1week) using Coralife's Iron Supplement as
well. I have 120w of NO Fl lighting consisting of 2 Phillips Ultralux and 2
Coolwite tubes, all a bit on the old side by now. pH averages around 7.0
and Iron seems to stay around 0.1ppm. Nitrates are at <0.2 (off the scale)
after more than a month w/no water change.

I've have the E cordifolius since starting the tank and it's never done
more that put up enough leaves to barely sustain itself, and all the leaves
it grown since I've had it are nothing like those in photo's or that it had
when I bought it (short stem, ~6"diameter leaf), but long 10-12" stems
w/sorry-looking ~3" diameter leaf. Is this a diagnosable/curable problem,
or a general symptoms of something wrong w/my system? (Both?)

Any ideas?  Thanks, in advance!

(I don't get the time to _regularly_ read the list, so direct Email would
be appreciated, though I'll eventually get the info as I do archive the
list digests.)