Re: [AGA Member] Red Pigment-K spectrum experiment

["Daniel Larsson" <defdac@hotmail.com>]

I was thinking if aquatic plants have much more tender and fragile
"skin", so CO2-uptake gets easier, they have to develop more
protective pigments as they get closer and closer to the surface/light, and
when they break the surface and develop "hard skin" they get green again?

This is the same L. arcuata plant (two stems from the same base):
http://194.236.255.117/defblog/pictureAction.do?method=view&id=1286
grown under Aquarelle (Triton-like) and SunGlo (yellow light).
http://194.236.255.117/defblog/pictureAction.do?method=view&id=1287
(you can see the yellow stripe where the SunGlo is at the surface)

The SunGlo doesn't seem to have the strong orange-red spike at 630 nm
as the Aquarelle has, and therefore I thought the L. arcuata had to
develop more red pigment to "protect" itself.

Nutrients maintained by JBL-testkits and Tom Barrs estimative index:
5-10 ppm NO3, 0.5 ppm PO4, 0.1-0.2 ppm Fe.

(No N-limiting, and when I've tried N-limiting the reds didn't improve
much - the reds came out when I boosted the PO4 and maintained
NO3-levels)

// Daniel.
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