"his experiment has provided additional
evidence that equal PPF does not necessarily
result in equivalent amount of mineral uptake.
Spectral quality may exert an influence on
mineral nutrition through related physiolog-
ical processes such as stomatal control, trans-
piration and carbohydrate translocation."
Quick excerpt from the pdf if you don't feel loke reading the whole thing. They've known since the 60s that spectral quality effects nutrient uptake. They do close the article by saying that ultimately you are better off making up for abundance or deficiency by altering your feed schedule than you are trying to use supplimental light to balance the problems that result. Or, better yet, use full spectrum light.