Leaf tips browning

Hello fellow grow folk. I been gardening now for about year and a half. Dont post much but read all yinz posts. Need an eye on a wwa that is starting to get some funny tips.

WWA from ILGM soil ffof, ff trio nutes although she is at 45 days and i havent given any thing but phd h20. Ph at 6.3 to 6.8, watering every 4 days, temps 75f day 65 night. Fans and 4 in exaust. 250 true watts LED light. 5 gal fab pot.
Havent seen this on previous grows.
Also have another wwa undet a HLG 240 q board light thoughts?
And what the hell…as long as i have an ear how bout this bruce banner photo in week 4 of flower under the 250 watt LED. Im sure ive got the setup wrong one blurple one q board and im not sure which light spectrum is better for the faze theyre in.
I will look forward to yinz comments.

yinzburgh by any chance?