Originally Posted by Wei
At least with my experience its the light intensity. I have rotala indica and only the tops of my plants turn gold and red once its closer to the surface. The bottoms of the plants always seem to be green. I'm at 3.8 wpg I dose iron, nitrates, and potassium twice a month after water changes.
If this were true why is it that folks had very nice reds, excellent color pre 1996?
Almost all the Dutch tanks, pics from here and Europe goign way back used NO FL's at 1.5, maybe 2 w/gal.
3.8 PC lighting is a lot more............and I've gotten good reds, as good as any with high light have at 2-2.2 w/gal with NO FL's.
Red tips are nothing new, this is because the Chl a has not formed in new tissue. Some plants have red pigments before the Chl a is added.
We see red tips as a result.
But the faster the growth rate.....they more % of the tips will be Red.
You can do this with adding plenty of nutrients and CO2, and also adding more light, but light alone is just part of that equation, not all of it.
Increased growth rates are a fuction of more than mere light alone.........
Low NO3 and high light is not a good comination.
Low light and low NO3 are a good combo, it's much easier to do and maintain a low level of NO3 and get that red stressed look people seem enamoured with. You can get some degree more reddish color with higher light in some cases. But there is a trade off balancing the low NO3 as that increases.
Chl a is heavy in Nitrogen, so limiting that, will induce red color(reduces the Chl a content in the leaves=> thereby showing more of the Red pigment that's noramlly masked by the green Chl a pigment). This will cause color changes faster and more dramatic in some species than lighting also.