HELP plant going yellow and crispy and clawing :(

What type of medium; soil or hydro? SOIL
What brand and type of soil? HORTICO potting mix with added perlite (very good drainage)
Indoors or outdoors? outdoor
What strain? Super Silver Haze
How old are the plants? about 3 months
What type of lights and how many watts?-sun?
How far from the lights?
What is your watering frequency and source of water? just tap water I know its bad and every 6 days temps are 30-40 degrees celcius
What, how much and when was it fed? NPK just recently a day ago. and power feeder which is 12% nitrogen ,Phosphorus 1.4% ,potassium 7% and potassium humate 3.08%. also use boost juice which is high potency Vitamin B1 (thiamine) and natural auxin.
What is the medium/runoff pH and PPM if in hydro? don't ph my water( should i do this)
What are the temps and humidity in the room?
What size pots? 50 litre
Any bugs? Look real close. had problems with spidermites none now and some black flies .
Any other pertinent info?..
hi my super silver haze seems to be getting worse and really need to know what is wrong with it so I can fix it.. it doesn't have root rot. recently re planted. and has big stable roots. I feed every 1 1/2-2 weeks. the sun gets very hot here sometimes 40c. is it a nutrient def?? also add in my preflower pistils seem to be going brown at the tips and my bottom branches seem to be bundeling up with leaves and not growing at all expicaly the bottom branches. and recently i have noticed the smallest leaves turning yellow and then crisping up and the bigger fan leaves just turning yellow and has stunted and it started clawing about 4 days ago and has gotten a bit worse since PLEASE help me i also maybe thinking nutrient lockout?

What BUDS said. . . Looks like a Nitrogen deficiency