Help Indentifying Issue

Hello all.I have 3 strains all from clones that are in week 3 of veg on 18/6 under 3 x 1000 mh. Temps are 26-28 and I have good vent as well.Anyway one if the three strains is showing some weird damage on leafs.I hopefully attached a photo.lol
Any help identifying would be greatly appreciated.Btw the strain showing these leaves in Purple Candy.

I should add humidity is constant around 50% and the markings on the leafs appear almost a gold/ bronze in color.

Medium being grown in is promix bx.I think my ph in my water is a little high.On a strip I'm getting 7.4-7.8 ish.The run off is too low for my strips to measure.I am going to pick a pen meter in the morning to be precise.So that being said any chance it could be a nute lock out due to high Ph?

Fish scales are from PH fluctuations.

Good jesus, PHing in the 7's?

/slap

No mr man, get your ass back down into the low 6's.

Thank you Lite.I am going to adjust in the morning and bring it into range.