Rotala macrandra (Re:lighting, peat)

Karen Randall wrote that
>R. macrandra consistently failed to thrive in my tanks.  I did not think it
>a lighting issue, since I knew other people with less light who kept it
> Finally, I tried potting it up with potting soil, laterite and some
>micronized iron thrown in for good measure.  Grown this way, I have had no
>trouble with it at all.


I agree that lighting is not the critical factor once the plant gets within
a few inches of the surface. I have a nice stand of it in a 70g tank (12-13
inch water column) which only uses 2 40 w. fluorescent bulbs and the leaves
are blood red.

This 3 yr old tank has a peat and sand substrate and does not get any added
nutrients except for a biweekly 20% water change (& no added CO2). The tank
has excellent plant growth, except for most of the crypts for which it was
originally intended).

Although, I may be providing needed nutrients through feedings and water
changes, I suspect that the decomposing peat is doing more than keeping the
pH down. Does anyone think that the peat may be providing iron and a lot of
other trace elements?