Nutrient uptake testing? Cutting back under higher powered lights

I took a look but couldn't find any information on how to test to determine how much of the provided nutrients are actually being used by the plant? Is there a reasonable way to do this? Also when upgrading to a much more powerful and intense light does the nutrients provided get reduced? If so by how much on average?
Thanks for the assistance as always

why not some ppm math? i doubt you'd get more accurate results unless you had a legit lab and top notch equipment.

more light=the need for more, not less, nutrients. maybe you're overthinking it?

I probably am lol. Smoking with too much free time on my hands

Tissue samples on new growth will tell you how much nutrients and in what %.