Just need a quick suggestion/confirmation

Entering my second weed of flowering and a few of my leaves are starting to yellow at the tips, my question is should i just add a little cal/mag next water? Also since i'm flowering should I add more n? Pics below

The first pick looks like a dead leaf just from being a dead leaf and what the plant waned off.

As far as a cal-mag problem I see distinct veins and yellowing edges. Could be cal problem if you are using tap water not a safe bet to add. If you are using distilled, deffinately. Could also be the onset of potas def.

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thank you buddy, using distilled but there have been a few times i said fuck it and went ahead and did tap.