A pic or two would help. 
It looks to be either wind or heat, Iām leaning toward wind. Do you have a fan right on it?
No. Only involved small fan 2 days ago and it is not blowing on plants using it for circulation. The temperature at plant level runs 75 to 78 . 2 days ago raised the from 24ā to 26ā.
Lights is what I meant by heat, you raised the lights because?
Light ir heat stress
I had read about being careful about height and strength of light on new seedlings . After a week I decided to raise them from the advised height of 24ā to 26ā. I was worried about burning them. What do you think I need to do to fix the problem?
Nothing just watch the height, you already lifted it so you should be fine. Keep measuring and moving it
The guys got you covered
If you are in soil I would try and bump my ph up to around 6.5. What is your rh humidity?
Low humidity will cause them to curl. Raise your lights for 3-5 days. Also a lil calmag in your h2o right now. Itwill work.