I took a few steps today. Thanks,
@Aqua Man for taking extra time and to share some very helpful knowledge.
I changed out my reservoir today with fresh nutrient solution. I used close to the directed amounts (~7ml/gal instead of 8) of Bloom, Micro, MagnifiCal each. I ditched the Astroflower (aka bloom booster) under the hypothesis that it was contributing to the problem with too much pk for late flower.
I also learned that with my super low ppm water, it is okay to use some PH UP (about 1 tsp/5gal) prior to adding nutrients and then finally adding PH down. I was struggling with 0.5 to 0.8 PPM swings over several hours. So I will be using my Potassium Hydroxide 34% for now, and shop for some potassium silicate to use instead.
With this mix, my 6.8 ph 30 ppm tap water went to 12.00, and ppm went to 150 after adding 1tsp/5gal.
After adding my nutrients to the water the ph went to 8.0 and ppm went to 850.
After adding about 3 tsp of phosphoric acid 34% the ph came down to 5.5 and stayed there with a PPM of 880.
I also changed the lighting, taking out the 650 actual watts of "full-spectrum" blurples, and replacing it with a single 240w V4 hl lm301b quantum led. Once I see no more signs of burning I intend to up the DLI incrementally by adding more lights.
This light has 512 pcs Samsung lm301B leds (even mix of 3000k and 4000k)+32pcs Epistar 660nm.
I have also changed from flooding every 3 hours 24/7 to only flooding during lights on. I used to just be too lazy to set the actual time on it. And am flooding at 50% greater frequency during that 12-hour lights-on period than I was before. (every 2 hours instead of 3)
Fingers crossed that the girls respond well and finish their last half of flowering on their best foot.
I will be cleaning up the dead leaves on the bottom and in the branches.
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