To me those all look great. Nice rich color. I would not guess that was below 1ppm of nitrate.hmmm… colour… so for example this:
The Blueberry wine acro, is that too dark or too bright?
Or this acro:
I personally like the colour but when I took those pictures I was not sure if it was too dark, or just right. At the time my NO3 was below 1 ppm…
Since those pictures I had major crash and I done few experiments and I am just not able to get same growth or colour:
For example the blueberry acro the purple is now gone….
This hobby can drive one bananas…
Anyway interesting subject and thank you all for sharing.