What do you mean by this?

"Now when I tried 6mg and below in it I was coughing like shit, but 9mg and higher, which is what I like and I am fine. "

I experienced this and tought it was my atty to blame. Even now...i use a not sogood juice with 12mg nic mixed with Menthol 0 Nic but waping at 6.5 Watts for a 1.8 ohm coil and...it is like...shallow...and scratches my throat. And when this happens...i ussualy turn the wattage down. Should i use more Watts or Higher Nicotine???