Wrinkled leaves?

I've been having recent issues with my leaves, and only on some plants and only in some areas, My leaves have become wrinkled/turning yellow a bit on the wrinkled one. I checked my soil ph and it was about 6.0 from the water run off. I give 12 plants 10 gallons of water while feeding them, and about 15 gallons while watering them, in 5 gallon pots. The water is around a 6.0 ph, and the fertilizer I feed them is about 6.0-6.5, it's low when I put the nuts in, but I raise it with baking soda. I don't foliage spray them, and I haven't gotten fertilizer on the leaves, the room is around a 40% humidity, and it's the first day of flowering today, it started about a week ago that I noticed the leaves were changing, I give them nutes and water them 5 days apart, when the soil feels like its dry enough is when I start to water them. Anyone have any ideas of what is going on here?

looks like minor N burn but i could be wrong. if its just a couple leaves or one plant i wouldnt kill yourself over it. your going to start on bloom nutes soon anyways and they have considerably less nitrogen in them so all should work out in time.