2nd run same problem. Brown spots

Newbie here, this is my 2nd run(different strain from the 1st) and same timing, week 5 into flowering. And the middle of younger/smaller leaves have brown spots in the middle. So from reading I figure its needs more cal-mag and or more P. But I don't want to add more of something it doesnt need and burn them. Also using canna nuts in promix. Tap water

Let her dry out before you hit it with nutrients..

Over watering can lead to deficiency because the roots get clogged, causing brown spots and ph problems. Let her dry and feed accordingly.

Thank you sir. I'm ph at 6.2