Re:Hyroo concerns

Tonid wrote, Oct 29:

>........Something is wrong - the
>thick, old stems are dying on me (becoming white and slowly
>disappearing) and some young leaves don't want to grow (they
>look wrinkled and shrunk). What could go wrong? The
>following actions could have lead to this:
>- - replanting (I replanted the Hygros two or three weeks ago
>to allow them to grow in groups)
>- - special Tetra plant nutrition stuck in the substrate near
>the roots (this should help, not destroy...)
>- - peat put into the sand near the roots
>- - liquid plant nutrition added to the water
>Which one (ones) could possibly cause this and is there a
>chance things get back to normal, or do I have to get rid of
>some of the mentioned elements (like do a water change,
>undig the stuff I put near the roots, etc.)?

Two possibilities occur to me.  The liquid plant nutrition and/or the Tetra
stuff stuck in the substrate may be too strong.  Sometimes high
concentrations of some nutrients, such as phosphate can interfere with
uptake of other nutrients, particularly iron.  If the young leaves that
don't want to grow are pale, then iron deficiency is a real possibility.  I
would recommend replanting them in plain topsoil with no nutrients added.
Do not push the stems under the soil.  instead, weigh the stems down with
small stones.

Another possibility is that you may be giving the plants too long a light
period.  Continuous light makes Hygrophyla grow small, distorted leaves
that are a dark, translucent green because there is no spongy mesophyll
with air spaces between the upper and lower epidermis.  I do not know how
long a night period is needed to prevent this effect; I only know that it
always occurs when the plants are given continuous light.

Paul Krombholz                  Tougaloo College, Tougaloo, MS  39174