Bolbitis herteroclita

[Diana Berberich <fishfaceid at yahoo_com>]

Hello Folks:
     Need the benefit of others expertise and
experience.  I have a single bolbitis leaf that has
numerous plants growing from it.  The plants clearly
are trying to emerge and develope but there is a
tendency for the leaves to become blackened. 
Everything else in the tank is thriving and lush.  I
use DIY CO2 and add Macro and Micro nutrients as well
as iron.  
      So, in the experience of others why this
tendency for the leaves to turn black, partially or
entirely.  I can't even tell if the blackened leaves
are dead or not.  The veins remain bright green.  The
plants continue to develope.
      Help!
Thanks, Diana

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