Leaf droop & curl.

Been flowering under a 750w HPS for a week now. Light is 28" over plants but one leaf has a droop and some have slightly "tacoed" over night. Waited a few hours to see if they would correct at all after turning the light back on (12-hour cycle) but no luck.

Could this be light stress? The manufacturer suggests even commercial growers to hang 20"-26" above. Some suggest lights being lower during flower stage as well.
Using just straight Foxfarm soil.

Thanks in advance!

Definitely could be light stress. What were they under before the HPS? When you suddenly put your plants under a much stronger light, it shocks them, you need to ease them into it. What are your temps like in there?

They vegged for 28 days under 750w MH 18 hour cycle. Temps are on the low side and well ventilated so heat stress couldn't be the issue. Also did the hand under light test and doesn't feel overly warm until about 16" from the light.

Just raised the light to 34" and will monitor closely.

Thank you!

Looks great, don’t stress.