Light burn or something else

Strain; Bag seed looks like indica

Ocean forest by Fox Farms in 5 gallon pot

PH of runoff or solution in reservoir?
What is strength of nutrient mix? EC, or TDS
700 ppm
Light system Spiderfarmer sf1000

Temps; Day 83, Night 72

Humidity; Day 35, Night 65

Ventilation system; 6 inch


I am trying to figure out whats wrong with my plant. This showed up last week (May 18)and been getting worse. Originally thought light burn and moved light from 18 inches to 21 inches. Did a flush last Monday (May 18), and fed half strength yesterday. Using big bloom and grow big by fox farms was supposed to start flower this past Monday (May 25)but i dont want to start with a sick plant.

This is one of the tops most effectived May 19

Same top today (May 26) plant just woke up thats why its droopy.