02-10-2018, 08:01 AM
Join Date: Apr 2017
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| | Re: The biology of the color "red"
Originally Posted by Phil Edwards
I visited Neil Frank a couple months ago and his plants are BRIGHT red as are Diana Walstad's, particularly their Rotala macrandra. What intrigues me is their general low Nitrate levels. Neil doesn't dose much but does have significant amounts of peat in his substrates and Diana don't dose at all, though the decomposition in her tanks puts off what her plants need. Both people can grow some very healthy plants under these conditions and they happen to be bright...
That got me thinking that perhaps in some tanks it's a symptom Nitrogen deficiency. Because the plants don't have as much food they don't produce as much Chlorophyll. Since Chlorophyll masks the other pigments the red coloration should come out more.
Although I haven't tested it yet, I feel red coloration also depends on the color spectrum of the light it recieves. Since the Carotenoid pigments are best at absorbing blue light, bulbs with a higher amount of blue output should encourage red pigmentation in the plants. I've received quite a bit of anecdotal evidence to corroborate this, but haven't done it yet myself.
Finally, light intensity. Most of us have had plants get redder the higher in the tank they are and/or as more light is shed into the tank. Some folks think this is a "sunblock" reaction. Without knowing the biochemistry behind it I'd have to disagree. If plants underwater need to protect themselves from the sun why aren't all land plants red? Wouldn't they want a blue pigment to reflect the harmful high blue/UV spectra? Furthermore, why are so many species of photosynthetic algae that live at depth red?
Here's some interesting information:
The Solar Constant, the amount of incoming solar radiation (insolation), that reaches the upper atmosphere is equal to 1370 watts/square meter. The SC for the earth's surface is between 800 and 1000 watts/square meter, depending on altitude and atmospheric conditions. That's an average of 800 watts/32 square feet at sea level under average open sky! Take into account the effects of humidity, clouds, and possible cover from other foliage and you're talking less than that.
Consider the average high light aquarium with 3.0w/g (165watts) over an area of 4 square feet (55g). Nature=100watts per 4 square feet, Aquarium=165 watts per 4 square feet, that's an increase of 65% over nature!!!
Are those plants are growing so fast under that much light that they can't produce that much chlorophyll? I think the more likely reason is that there's so much light getting to them relative to their needs that they don't need to expend all that energy creating excesses of pigments they don't need much of.
Insolation and solar angle would also explain why FAN's plants are redder than Tropica's. The greater solar angle in Denmark decreases the amount of light available to the plants vs. the pretty direct light in Florida.
i just got done reading this thread and phils post(s) stood out to me the most.
I dose EI with the NilocG mixable dry fertz, so... i dose 10ml of micros And macros every other day (dif days for each, dont dose sunday) in my 40b... Should i increase dosing? or even triple this?