When your dropping your lights , I’d watch the top fans for color loss, not the pistils.
The fans will change first .
I would lower a little, and watch, and hit the canopy with a temp gun. Monitor the temp .
The closer you run to the max the more you should watch this table .
Going to 3500k means 50% lose of light , I wouldn’t do it .
But something is up with that light setup.
You are running LEDs to save money I’m guessing . But if they are taking 50% longer to finish a crop , are you saving ?
I love math and numbers , they don’t lie, it’s right or wrong. I ran the numbers on LEDs when I built my last room.
Bang for buck , $ spent per year , new release of technology, LEDs are not for me just yet.
I’m seeing signs of nute burn, even when they have been “fluffed”
Water (pretty much everything) follows the path of lease resistance, when your flushing the water will want to flow out this path, it takes a lot of water to get into the ball .
This is why I keep checking , when you 1st start seeing run off , it will be close to the same as what your adding , but as you keep going you can watch the ppms climb
As long as its climbing your not done,
I use to flush with straight RO, and after I was done the last water would be a weak feed. but after some debate with memebers n testing , I use about 15-25%ppm as the plant has been getting .
And don’t let it dry right out, this will also pull more salt out of the medium, rising ppm.
I would run a “known” strain in that system to cross reference the data.
Next run grow whatever you want , but maybe seek out a clone to put in there and see what happens .
If my PBK can finish in 49-56 days in my system, and takes 80-88 in yours you’ll know the lights need to be addressed.
If it finishes in 63 days , I’d say they are ok.
And the B.B. is the right strain for your grow.
I do think your system will take longer no matter what light , because of the amount of CO2 I pump into the room. It really gets things moving .