Re: Holes!

[Chuck H <grendel at usit_net>]

Ghazanfar Ghori wrote:

>New growth in my dwarf sags and E. tennelus is
>showing signs of some kind of deficiency. Atleast
>thats what I think is causing the problem.
>Take a look: http://www.aquaticscape.com/temp/sag_holes.jpg
>
>Any ideas what may be causing this?
......

It could be due to an iron shortage.  I have some E. tenellus that used to 
develop the same kind of holes in older leaves that your photo 
shows.  Other Echinodorus and Vallisneria species were having problems with 
older leaves, too.  New leaves were coming in somewhat transparent.  I was 
adding around 20mg/L of potassium per week (via K2SO4 and KNO3), so a K 
shortage was unlikely to be the problem.  I bought an Fe test kit and 
discovered that my trace supplement wasn't adding any measurable Fe despite 
the fact that I was dosing well above label recommendations.  I started 
adding extra Fe and soon learned that my tank had indeed been Fe limited -- 
NO3 consumption increased by about 50%.  The Swords and Vals, as well as 
other plants, are much improved since then.
--
Chuck Huffine
Knoxville, Tennessee