i need emergency help with yellow leaf and droopy seedlings

[Weed131313]

Hi guys I really need help with my plants . I planted my seed in cocopit 3 weeks a go .About fertilizers just today i have give them just a low dose of biobizz grow . My LED lights are 60 cm away from top of plants and my lights are white and purple . As u will see in the photos the lower set of leafs are yellow and burnt also some of the other plants are droopy and even turning yellow
I think they are over watered thats why plants are droopy , even due i didnt water them much but the humidity was about 90% during this 3 weeks but now i set that to 65% . Also trying to give them less water .
i have 2 other plants that they just dont grow it looks like they are locked . When should i start fertilizing?? Please share your ideas so i can save these plants

[vostok]

Too Hot a soil and feeding too early will nute burn your plants

IMO extract

wash roots in air temp ph'ed water

re plant in clean mix with 30% perlite

you can add the used soil later once much larger at potup

good luck

[Weed131313]

My soil in Coco perlite and its sterilized and also dont have extra nutrients .. could light and over water could burn them like this ?

[Greenlivin]

Are you Ph'ing your water after adding nutes?

[Weed131313]

No i havent but only one time i have fed them with biobizz grow

[CaptainWiese91]

Every water and every nute feeding - PH always.
But it’s not too hot soil when it’s coco perlite - could be as greenlevin is suggested.