[Bob-Smith]

Interesting article comparing the two.
https://science2be.wordpress.com/201...d-chlorophyll/

[Phaeton]

https://plantphys.info/plant_physiology/light.shtml
Another site on chlorophyll, with charts of all four common types.

The similarities of hemoglobin and chlorophyll structures have been shown.
Light penetration to the chloroplasts in the leaves and why HPS grows heavier plants than HID is explained by hemoglobin similarities as well.


Red and blue light do not penetrate past the first layer of chlorophyll, the red and blue wavelengths are stopped by active chlorophyll. Green light does get through. In normal full spectrum light only one out of seven photons of absorbed light are green. The graphs show green way down on the bottom.

The inside of the leaf is all green, the red and blue are blocked. The plant makes additional chloroplast layers to use this green light. HPS is orange and green, no blue and very little deep red, forcing the plant to grow a great many layers of chloroplasts to use this abundance of green. The result is a heavier plant.

The hemoglobin connection: Blood is red, except when it is deep purple. Bleed and it is red, actively carrying oxygen. Veinous blood is deep purple, it is not active.
Chlorophyll is the same, it is green when active and deep purple when inactive.
This means the the leaf is green because all the red and blue are stopped at the surface and can go no further.

An outdoor plant at the height of summer will get over half it's total energy from the green spectrum. As the intensity falls off the percentage of green used goes down as well. When the intensity falls to half or less the green wavelength usage falls to seven percent or less.

This complicates dialing in the spectrum because as the intensity goes up the spectrum the plants uses changes. Putting in more of the same spectrum lights used at low levels does not mean maximum growth at maximum intensity, green needs increased more than blue and blue needs increased more than red.
Balancing the spectrum with the intensity is the most difficult part of dialing in a high efficiency bud room.
Almost all off the shelf equipment is designed for medium light levels, tinkering is required for running at the edge.

The connection between chlorophyll and hemoglobin helped me understand how the light needs change depending on the light. Very confusing circular logic that nature uses without having to think about it.

Plants in iron rich areas contain hemoglobin as well as chlorophyll due to random substitution of similar sized ions of iron instead of magnesium. Evolution wise this is where animal blood got it's start.

[TracerChris]

Wow this is really good stuff! I wish I would have known about this connection sooner

[Drewsif]

Mammals are just plants with their roots turned inside out and connected to their mouths.

I was thinking the other day, if any of the snake oil bottlers have ever sold liquid chlorophyll as a nutrient. Hell, they bottle everything else the plants produces itself.