Colors and lighting

I'm getting some strange coloration effect in my plant, which I would have expected to be just the other way around.

soil atami coco mix
biobizz grow,bloom,topmax

setup is 2x400

The left bulb is new, the right one is suposedly in its last run this cycle. (twas freebie >_>)

I got bit of odd color effect in my plants, I would expect that the plants under the new light(first run) would be doing better, greener, healthier, cos of the light.
But the opposite seems to be happening, only in color atm though, but I'd rather be safe then sorry.
Plants on the right, below the old bulb are greener, then the ones on the left.

A slight note about plant states:
I had some air leakage before last week putting one plant in the draft, which lead to the bottom left plant ending up now with a lighter color and is slower getting a darker color, by now its already doing great again and the buds are forming just like the others. Now, the center plant has way more buds then the others cos of a very good fim, it requires a bit more feed then the others, and also has a slight lighter color, nothing to really worry about for me.

Thus two somewhat lighter plants, (center and bottom left) are already a bit lighter

Then I have this:


At first I thought that the older bulb simply gave a darker (less light) effect, superfiscially and on camera effect, but its not.
If you look to the top left and top right, both are doing equally as impressive in size and water uptake, only this coloring sets me off a bit.


Is the darker plant color bad ? or signs of anything being off ?
And of the two, (top left, top right) which would be considerd healthier ?

If there is a considerable lumen difference, should I change light height so height difference can compensate lumen difference ?
I have no light sensor or anything to test lumen atm though.

What you are seeing there is

Plants under the light on the right aren't needing as heavy nutes as the ones on the left.

If the right side is your older bulb it means its lumen loss is alot more than the one in the left. Therefore plants aren't growing as vigorously as the other side and therefore need less nutes.


The opposite is true for the left side.

New bulb = more vigorous growth
More vigorous growth = greater demand for nutrients thus yellowing slightly because they aren't receiving enough nutrients.


Advice.

Reduce feed strength on the darker plants and increase strength on the lighter plants.

IMO next time if you can afford it get 2 new bulbs to run together.

Out the then one grow bulb into spares incase of a blow out.



J

And top left healthiest.

Then centre plant.

Then bottom left

The take your pick of the others.

IMO its easier to correct slight under feeding than it is over feeding. That's the reason my healthiest list is the way it is.


The 2 to the right do they have quite leathery feeling leaves? Very dark green almost purple leaves. This is the beginning of N toxicity.





J

Ohw thanks man, that makes perfect sense !!!

The darker plants do not feel leathery, but more stiff paper-ish .. hard to describe, and its not purple, but really dark green. Perhaps it will swing in that direction if I keep the current course.
The N thing totally connects, I added some extra a couple of weeks or so ago with an NP additive, cos I needed P for a slight phosfor deficiency.
I'll stop/lower the N on the darker plants, and will see if it looks lighter in a week, hope so, from what I read toxicities are real bad.
I was under the impression this phase of my flowering I had to pump up the feed for a week or two (second week). (day 72, just started 4th week of flower )
I'll go lower again, thanks a lot.

And indeed, its a good idea to get ne 2 new bulbs; I was planning on doing this run for with one light, but stumbled myself into getting the second for free with balast.
But its making too much a difference, so I'll try and get 2 new bulbs asap.

Thanks again, I was under the impression the darker did seemingly better, but I am mistaken.
Sorry I cant rep you, need to spread more of it myself first apparantly -,-

I like to try and maintain what I call a nice lush green.

Not too dark and not too light.

Maybe a little darker than top left. But not as dark as bottom right.

Don't get me wrong you could continue on and it wouldn't hurt too much unless you started getting N tox claw.



J

Ah, I try to keep an eye on the overall color of the plants too, and also check the bottom leaves a lot.
I havent trimmed any of the bottom yet, but also used it as a slight indicator about the plants feeding behaviour.
I can see the plants occasionally eating away a couple of the lower leaves, ofc this is also due lack of light, but they are getting eaten evenly, as in the plant wants/needs more food.
And acted accordingly, will keep a closer eye on the N's, I hadnt linked it to the very dark color, but will try and influence that in a positive way with hopefully a lighter outcome ^_^

Do you have any images for the N tox claw symptons?, I googled but couldnt realy find an appropiate one.

I don't have any pix.

But if you google "nitrogen claw cannabis" you'll see what I mean.

Its where the blades of a leaf fold downward and inward on themselves. Creating a claw shape. Others call it eagle claw.




J

Thanks, found ehm. Hmm, have to say, none of the leaves doing that atm, so if its that, I hope I caught it early thanks again