Seedling help! Wrinkled skinny leafs

Seeds were started in happy frog in 72 cell trays. Had stretching problems so I repotted into solo cups. Have been using plain water. Is this burn or a watering issue? Thanks in advance.

Yikes!.. gonna need more info. Soil type? PH? Water schedule? Drainage?. Temps? RH?. PPM of the water? Some pro's here will jump in. I dont really see any abnormal stretching, but sick plants anyways.

could be a lot, yes let us know what you have been doing to these seedlings...off just the images looks like nutrient burn...but that's a blanket term..

Soil- happy frog
No nutrients just plain tap it's running 160ppm
Watering everyday
Drilled 5 holes in cups so I would think that's ample
4 bulb t5ho light
Temps 70-75
Humidity 40-60%

RH? Sorry this is my first indoor grow.

RH=Relative humidity. If all that is correct, I would make sure your PH in the soil is in the correct range. They do not need water every day. Wait until the pot is super light before you water again. This could be 3-5 days, depending. My first guess would be they drown. Make them search for roots, as that is what they do during the first 2-3 weeks, then they start putting on the vegetation.

Do I check run off? Ok I will let them dry out and see if it helps.

Dont water everyday, let your soil dry out, not all the way. But overwatering , which with plants this small and with your type of nutrient delivery (the soil), water is feeding and watering is over watering...less watering more dry down, the perfect amount of water is a days supply...which with these younglings is probably like 30-50 ml maybe, but definetly feed mote and allow dry down so your roots grow more and faster

I feed seedling with full leaves, 3 sets, 500ppm + at this stage...im feeding these week stem fucks full strength once a weak and water any other time

Ok will definitely cut back on watering. Hopefully they will recover. Thank you for info