plant help.....

Hello all!

I have developed a problem in my 55-gal plant tank.  This is a relatively
recent set-up which used to  be in a 30-gal.  About 2-1/2 weeks ago, I
received a shipment of plants and replanted the entire tank.  Here's my

While most of my plants are doing well (hygros, crypts, crinums, anubias,
Barclaya, and several stem plants etc.), I seem to be having a problem
specifically with three large Amazons and several Apon. Crispus.  The
Crispus are blooming and putting out shoots to the surface of the water,
but their leaves are steadily turning brown and/or transparent.  The
Amazons are also developing yellow margins which gradually consume the
leaf until I have to remove it.  This isn't for lack of iron, as I
fertilize with Seachem's Flourish as directed on the bottle and have also
added several laterite balls in the substrate.  It appears as though they
are being burned (as an outdoor plant would do if left to dry out in the

I also have a problem with several vallisnaria spec. - the leaf ends -
about half way up to the tip - are going "soft" and transparent.  They
have been planted correctly with the crown of the plant above the
substrate, yet I can't seem to stop the progress of these "melting"

As for my lighting set-up, I currently run two 40-watt vitalites for 12
hours daily, with a 4300k metal halide running from noon until 5:00 p.m. 
Tank temp. gets to about 80 - 82 degrees, but I am running a fan to
control this.  Substrate is 2 - 3 mm in size and about  3-1/2 inches

Anyone who has a clue as to the cause of my browning Amazons and melting
Vals, please give me your input as I am at a loss to explain it.  None of
my several plant books seem to address the issue.

Thanks in advance.....			Tara T.