problem with wrinkled leaves... any ideas?

Im having problems with wrinkled leaves on all of my young plants (one plant is especially bad). However, for some reason the larger plants directly to the left of the smaller ones are doing great. They are all recieving advanced nutrients' ph perfect sensi grow formula with b52 booster and hydrozyme enzymes. I feed once a week and water with tap water at a ph of 6.3. Here are some pics. Any ideas whats wrong? I know I'm going to hear "ph problem" but the healthy plants are receieving the same ph perfect nutes and also sitting around 6.3 so I dont see how it could be a ph problem.

I wouldn't worry too much about that..overall the plant looks great, although that lighting could be better for pics...lol.

Are they all the same strain? Could be an environmental reaction from the specific type of plant. Merely a guess.

the weirdo freckling on that one leaf bothers me more than the crinkles, but I have no idea what will do that...so sorry I can't help...there is a good chance that the best answer is to leave it be and see if it gets worse

yeah, I wouldn't worry at all...those plants look really nice.

Yes very beautiful BTW.