Heat stress, boron defiency or something else?

Hi guys, im in the end of first flowering month and starting seeing some problems. Im growing northern lights in soil with biobizz nutes, with 250w hps.
First, the two highest colas is experiencing some problems on the top. Have some kind of burnt spots on the leaves and theres not much flowering on the tops. Its about 30C heat around those tops.
Second, the tip of some leaves in the middle of canopy became white or little burned, so ive decided its nute-burn or something going on with ph and flushed with a plain water of 7.6 ph just to test the runaway, which was about 7ph.

Any sugestions?

Anyone? Some help would be appreciated

For one you're at the top of the temperature range, you don't want to get any hotter. I don't use LEDs, but make sure you're not too close

A fan blowing not on the tops, but between the tops and the light to take away the Heat will help

..may be a Cal/Mag related issue, why are you putting your pH in so high, adjust to 6.5 & maintain there.

I don't know your nutes, but when I have weird things show up I'll tend to flush it lightly w/ plain pH 6.5 water, then go back in half strength next feeding and see if it improves before I move on
-good luck!

Them leaves look awfully dark.. looks like you're getting nitrogen toxicity.. easy up some on the nitrogen and with soil, you shouldn't adjust the pH of your water.. quality soil has buffers in them which will regulate the pH levels..

They are looking hot from temp and nutes.

Hot temps require a reduction in nutes because of excessive transpiration.

Maybe play with the circulation fans to get the heat away from the canopy like mentioned above.