Nutrient burn?

I have a little bit of browning on my leaf tips and suspect it is nute burn as I have been upping the dose gradually.
I am growing in DWC and temps are low 70's high 60's.
pH has been a little higher in the morning, adjusted at least daily to 5.5-5.9

My question is: do I back off a little on the nutes when I change res. water today? Or, should I flush with plain pHed water for a few days?

Thanks!

Yea that's the starting signs of nute burn if they don't burn anymore your fine a little tip burn just means it's feeding just don't over due it maybe cut back a fraction on the nutes

Pic 2 looks a bit bad maybe cut back more then fraction

Yah your feeding to much. see how green your leaves are? they shouldn't be that Green.
That's the first sign of to much (N)
You'll be good man just back off a little bit.