I run at 1.8+ but my water is at 150ish and I have to feed twice daily in 5g pots or else get some tip damage, nothing that impacts bud growth but annoying.
What I do is drop the base feed with nitrogen by 10% (cocotek in our case) and increase PK to bring it back up but its hard to keep at 1600 in full bud production as you are also reduce CA and MG with that 10% drop and we know how that is.
Pot EC is your point of concern measuring runoff EC can tell you a lot on that, feed frequency or ratio may need changing based on that.
"Coco for Cannabis" Dr. MJ Coco Amazon or his web site, get that book