Re:Cordifolius not growing

>From: "Matt McCabe" <mbmccabe at coil_com>

>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?)

The long petioles and small leaves are almost certainly symptoms of
insufficient light.  Most, if not all swords require an open, unshaded
area.  This is especially true for cordifolius, which is less adapted to
submerse conditions than many of the other medium to large swords.  Of
course, when you give it what it wants, cordifolius sooner or later starts
producing large emersed leaves and you have to whack it back to discourage
it from pushing off the tank cover.

Since you report that crypts are doing well in that tank, I am wondering if
your cordifolius is showing any nutrient deficiency symptoms.  Are the
older leaves turning yellow and dying from the edges inward?  I suspect
that crypts can compete for nutrients better than swords, because I have
had a tank where crypts were looking good, but the sword (amazonicus) was
seriously deficient.  When I really pushed nutrients, the sword greened up,
stopped losing its older leaves, and started producing much larger leaves.

Paul Krombholz                  Tougaloo College, Tougaloo, MS  39174
Goofing off instead of working in spring-like Jackson, Mississippi.