What's this? Slight browning on a few leages.

[Jason]

Just changed nutes to Week IV of the GH Trio recirculating feeding schedule.
I noticed a few larger fan leaves have some slight brown splotches. Not at the tip, but back a bit.
Not all leaves, maybe 3-5 on two plants. All larger leaves, not near the bottom and not right on top.
Temp 72-75 F and humidity 35-50%. pH is fine and everybody looks very healthy.
Light is a 315 CMH at 22-24 inches.
Thanks for any insights.

[Euroaznscotty]

Pics will help us help you!

[Jason]

Sorry. I was being lazy. I've cut the ends off 4-5 large fan leaves. Smaller leaves and those at the top and bottom seem unaffected.
Could it be wind burn due to my fan? Just tossing something out there.,
I've using GH Flora Trio, third grow, with no previous problems or this look.
Thanks again for insights.

[Jason]

I clipped the offending ends off a few leaves. So far no more leaves show the effect and the trimmed leaves appear healthy.
All other appearances are perfect. A little stretch is starting in Transition with the 12/12 schedule.

Just added 1/2 gallon H2O to each WaterFarm. The girls are getting thirsty. pH was about 6.5 this morning after being 5.5 late yesterday afternoon.