Ionic grow nutes at 220 ppm, ro water pH 6.0 5 gallons to bottom of cups. 3 1600 lumen led's covers removed . 4 Cat Piss one 2 day old ww..All regular seeds going for a cross pollination box . Doing the prayer method for at least one girl.
Last time I saw this in a batch of seedlings it seemed to be a CalMag issue. I added a little CalMag and the warpy leaf thing cleared up. Not sure if that is the cause but thats how it worked in my seedlings a couple weeks back. I was using a 3 part nute system and it just doesn't always seem to provide enough of those 2 minerals.
My seedlings seem to always do this and in the veg stage when things are growing really fast.
PS, I had to go really easy on the CalMag because the first time I raised the ppm on the seedlings a little too much and stressed em a somewhat. They recovered ok in the end though.