Re: [APD] Notes on the notion of high K+ causing Ca++ inhibition

[Dirk_Matthys at toyota-europe.com]

Just an observation.
Ammania Senegalensis is growing great in my 75 G . Nice colours of red,
tone of red is changing from time to time due to NO3 concentrations. At
least that is what I read on the list as a possible major influence on red
colouring. I have some periods where the growth is uniform, nice long
leaves with good and regular internnodal distance, fat stems etc... But at
certain times , possibly after major water change ( I work on a 14 days
major and one week minor water change schedule ) deformed growth shows up.
Not just a little bit. I am talking about small leaves , only 1/3 of the
normal leaves. very small internodal distance, and the leaves are crickled
and twisted in all directions. The colour is also very red. I have always
wondered what causes this deformation. If i look at the nutrient deficiency
symptom chart I would say it comes closest to Calcium deficiency as a
description. But my water is at 10-12 Dh ( german hardness units ) which
should be enough calcium ( and KH is about 6-7 ).Any idea if this could be
the issue , Any other way to proove this thinking?

about the tank:
 I use the Tom Bar method of resetting the tank through water changes with
nutrient replenishment and very recently I started dosing PO4 .  I used to
have no algae while planth growth was quite fast but not so good looking  .
Since PO4 dosing the colours and shapes are much better. ( I try to keep
PO4 between 1.5 and 0.5 ppm, I am in the learning period of dosing PO4 so I
measure every day to know what is going on and correlate to how the plants
look and react ) . I also dose K and quite a lot ( it was the best
improvement  to my plants when I first started with PMDD ) . Reading the
subject notion of high K I was wondering if this could be the issue here .
My other plants do not have a problem at all, just the Ammania. (  NO3 and
PO4 , TMG are all dosed more or less properly and I make a dosing check
measurement every 2 months or so ) . My tapwater is medium hardness , has
about 7 ppm of NO3, PO4 unknown from he tap.

specs:
( 75 G , 220 W T8 with refl. , CO2, TMG,  K2SO4, KNO3, KH2PO4, medium
fishload , by-pass terestrial plant filter and closed wet-dry system,
laterite-mulm- gravel substrate  )

suisoman Dirk

_______________________________________________
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com
http://www.actwin.com/mailman/listinfo.cgi/aquatic-plants