burnt tips...6th week of harvest

hey everyone, were experiencing light yellow leaves with burnt tips....almost finished in flowering, at 6 weeks. i watered tonight with cns ripe and thats all and hen next week i will flush....any input, thank you!

to much heat or not enough water or ph could b off ,lots of things could be wrong cant really give u to much imput based on the info

ok thank you, the lights arent too close to the plants, i have very adequate airflow, ph of water has been between 5.8-6.1 and the soil ph has been steady at about 6.8. and ive been using a soil meter to determine on when to water

yr ph is low on yr water 6.5 for feeding for flower and u can keep it around 7 for veg but as for the soil thats fine, so ph is yr problem , the plant cant take the nuts up so now u have a deff

a deff? but ok i will raise the ph of the water! what should my run off water ppm and ph be after flush.....