Random few leaves dying

They are about 2 months old and they just started to turn. I tried looking at pictures of different deficiencies but I can't figure it out. Please help first grow. I use proper ph water and ff grow big nuits, they just got put under a 400 mh could it be burns? The dying leaves are mid way down to lower section.

Looks like a pH problem. I know you said you're checking... How are you checking? What soil are you in?

Looks like the plant is mutated as well. Irregular leaf growth and such.

The general hydroponic basic test kit. I know it's not the greatest, but I haven't had any issues until now and my 3 younger ones are ok. I did research about the three leaves and they said that it happens with some OG's. They're in fox farms ocean forest and a touch of all organic miracle grow soil. Been in same soil for a few weeks without a problem.

URBAN GARDENER : I found a site on International Cannagraphic with the whole rundown on deficiencies with pictures, it might take a bit to find the right spot. I hope this helps.

Agree with @DirtyMcCurdy .. id also like to know what you use for checking pH and what pH are you using.

I don't currently have a soil tester, I thought Ocean Forrest was good how it was. I use the General Hydroponics ph control kit for the water.