seedlings look bad

what is wrong with them? I thought maybe heat?

Have you been feeding them? they look burned..

but the pictures are really small

Looks like nute burn.. bigger pictures please.

sorry only had my phone. I have been using tap water but have been PHing it to 5 then some super thrive. the other plants look much better that are getting fed the same stuff

Hmm thats odd. Idk im a nood But I would like to know what it could be if i ever run into something like it

Tell us a bit more about your setup.

You need to take a close up pic of the leaves!
How long have they been in the cups?
Pop'em out of the cup and check the roots!
What kind of dirt/nutes you're using?
I took a 2nd look what is that 100% perlite?
Is this some type of Hillbilly hydro?
I'm doing hillbilly hydro but in rock wool!
With the little info I have right now I'd
vote nute burn!

they are like mini hempy buckets. I am starting them 75% perlite / 25% RW. then moving to 1 gal containers for ebb flo. I think they are nute burn also I am all water flushing

What are the temps in the room with lights on, lights off.
What lighting system are you using
Air?
Nutrient of any sort?
Additives?
Strain?
Age of the seedlings?

humidity domes, super thrive, multiple strains, 3 weeks

you just said you feed them water with ph of 5?

5.5 or so but it is ph'd tap water with superthrive

in soil use ph of 6.5

its rw and perlite

Some better pics would really help, but something is clearly wrong.

These are only like a week old. Put into a towel on 7/28.. planted on 8/2. The little one was like 3 days later. In rockwool and hydroton. Watered with pH 5.6-6 water.

yeah mine suck I need to fix them asap

Oh and mine are only 12/12 from seed, no veg.

haha nice I am trying to make mother plants for cloning thats why i have so many different strains going

if i'm not mistaken 5.5 is too low for most plants after they've popped... You have ANY nutrient with castings or guano? You can take your tap water and add the appropriate amount of nut to help even out it's ph, should be around 6-6.5 I believe... If all else fails stick to what you know right? Did you say you have your seeds under 12 hours of light?

Pretty sure he is not using soil, where pH 5.5-6 is what you want.