Re: Green surface film, pruning Vallisneria

> From: Andrew Hamilton <andrewha at tafe_sa.edu.au>
> Subject: Algae re-post
> Has anyone had experiences af a film of (initially
> appears white in its early stages) lime green algae accross the water
> surface? 
	I have similar stuff.  It seems, in the one tank where I have it,
to be associated with higher iron (and possibly other trace element)
concentrations.  This is also the tank into which plant tabs were placed
quite a while ago.  I suspect there is still more phosphate there than 
is ideal.  It does not seem to be related to the nitrate concentration,
in that changes from <1 ppm to about 8ppm do not make any discernible 
> From: Elizabeth Worobel <eworobe at cc_UManitoba.CA>
> Subject: Re: Cropping Vallisneria
> DONT! Why ruin a beautiful plant?
	If I don't do something about mine occasionally, the water surface
is taken over by 2m long leaves.  They are indeed beautiful, but nothing
else gets much light.

Paul Sears,     Ottawa, Canada